HyperthermiaNCT06670365
Enhancing Heat Resiliency in Older Adults During Indoor Overheating Via Heat Acclimation by Warm Water Immersion
A study testing Heat acclimation by warm-water immersion in people with Hyperthermia and Thermoregulation, run by University of Ottawa at 1 site in Canada.
Trial summary
As overheating in buildings is expected to increase as global warming continues, proactive measures to increase heat resiliency in heat-vulnerable older people are needed, especially for those without access to home cooling or reliable sources of electricity. Read more about this study
- Who is it for?
- Ages 65 to 85 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Hyperthermia, Thermoregulation, Aging
- What is being tested?
- Heat acclimation by warm-water immersion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteCanada
- Study dates
- 11 Nov 2024to 18 May 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 to 85 years
- Women only
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Non-smoking.
- English or French speaking.
- Ability to provide informed consent.
- With or without a) chronic hypertension (elevated resting blood pressure; as defined by Heart and Stroke Canada and Hypertension Canada), b) type 2 diabetes as defined by Diabetes Canada, with at least 5 years having elapsed since time of diagnosis
Who cannot join
- Episode(s) of severe hypoglycemia (requiring the assistance of another person) within the previous year, or inability to sense hypoglycemia (hypoglycemia unawareness).
- Serious complications related to your diabetes (gastroparesis, renal disease, uncontrolled hypertension, severe autonomic neuropathy).
- Uncontrolled hypertension - BP >150 mmHg systolic or >95 mmHg diastolic in a sitting position.
- Restrictions in physical activity due to disease (e.g. intermittent claudication, renal impairment, active proliferative retinopathy, unstable cardiac or pulmonary disease, disabling stroke, severe arthritis, etc.).
- Use of or changes in medication judged by the patient or investigators to make participation in this study inadvisable.
- Cardiac abnormalities identified during screening
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluating the Efficacy of Heat Acclimation by Warm Water Immersion for Mitigating Hyperthermia and Cardiovascular Demand in Older Adults During Indoor Overheating.
As overheating in buildings is expected to increase as global warming continues, proactive measures to increase heat resiliency in heat-vulnerable older people are needed, especially for those without access to home cooling or reliable sources of electricity. While short-term heat acclimation through exercise in the heat has been shown to increase heat dissipation and decrease both the physical and mental stress imposed on individuals exposed to heat, such protocols are not tenable for older, sedentary adults. A recent report showed that seven consecutive days of warm-water immersion improved whole-body heat loss and reduced physiological strain as assessed during an exercise-heat stress in habitually active older men This represents a critical finding as an increase heat-loss capacity would serve as an important safeguard for older adults exposed to indoor overheating due to lack of air-conditioning. While this preliminary data highlights passive hot water immersion as a promising strategy for increasing heat-resilience in vulnerable adults, work is needed to confirm its efficacy in more "real-world" environments. Thus, this study aims to assess the effectiveness of a 7-day passive heating (warm-water immersion with core temperature clamped at ~38.5°C for the final 60 minutes) protocol in mitigating increases in thermal and cardiovascular strain in older females exposed to daylong (10-hours) indoor overheating (36°C, 45% relative humidity) prior to and following the passive heating intervention. Relative to males, females have a reduced heat loss capacity (~5%), which is driven by differences in the activation of heat loss responses (i.e., skin blood flow and sweating). Although there have been mixed findings with regards to the influence of sex as a mediating factor for heat-related mortality, some studies suggest that females are at a higher risk of heat-related mortality and morbidity compared to males, especially amongst older individuals (≥65 years). Notably, a greater proportion of older females died compared to their male counterparts during the 2021 Western Heat Dome. While the underlying causes for these differences remain unclear, greater cardiovascular strain may place females at higher mortality risk during extreme heat.
- Being tested
- Heat acclimation by warm-water immersion
- Keywords
- thermoregulation, heat illness, heat acclimation, extreme heat events, women, indoor overheating, water immersion
- Medical subject headings
- Hyperthermia, Heat Stress Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heat acclimation by warm-water immersionOther
Participants will be immersed in a whirlpool tub to the shoulder level in a circulated water bath maintained at ~40°C until their core temperature achieves a steady-state of 38.5°C for 60 minutes. The warm-water immersion protocol will be repeated for 6 more consecutive days.
| Study group | Role | What they receive |
|---|---|---|
| Daylong exposure to indoor overheating | Experimental | Prior to and following the warm-water immersion protocol, participants will undergo a 10-hour passive heat exposure where they will remain in a climate-controlled chamber regulated at 36°C and 45% humidity (temperatures experienced indoors during extreme heat events in North America). During this time they will remain seated with the exception of hourly 5-minute breaks to stretch. Receives: Other: Heat acclimation by warm-water immersion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Core temperature (Peak) during daylong heat exposure
Peak rectal temperature (15 min average) during exposure. Rectal temperature is measured continuously throughout the 10 hours of the simulated heat wave performed prior to and following the 7-day heat acclimation by warm-water immersion.
Measured: End of 10 hour daylong heat exposure
Secondary outcomes (29)
Muscle oxygen during battery of cardiovascular, cognition and postural stability tests during daylong heat exposure
Participants will be attached with 2 probes to measure tissue oxygenation on two locations via a non-invasive tool: near-infrared spectroscopy (NIRS). The device (Portalite, Artinis Medical, The Netherlands) is placed on the left prefrontal cortex and muscle belly of the vastus lateralis. The change in tissue oxygenation at both sites will be assessed as a percent change from baseline.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Profiles of Mood States (POMS) during daylong heat exposure
Potential changes in mood (7 subscales of mood: tension, anger, depression, fatigue, confusion, vigor and esteem-related affect). The POMS-40 is a validated, self-administered questionnaire that examines seven distinct aspects of mood state across two positive subscales (Esteem-Related Affect, and Vigor) and five negative subscales (Fatigue, Tension, Confusion, Anger, and Depression), which are described across 40 distinct adjectives (reference). For each individual item, participants were asked to describe "how you feel right now" by responding using a 5-point Likert scale (0 = "Not at all", 1 = "A little", 2 = "Moderately", 3 = "Quite a lot", or 4 = "Extremely"). The values of items associated with a specific subscale (e.g., Fatigue) were summed to calculate its score.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Core temperature (AUC) during daylong heat exposure
Area under the curve (AUC) of rectal temperature (in degree-hours) during the 10 hour simulated heat wave exposure performed prior to and following the 7-day heat acclimation by warm-water immersion.
Measured: End of 10 hour daylong heat exposure
BTrackS Balance Assessment (Postural stability) during daylong heat exposure
To assess postural stability, participants will be asked to stand on a BTracks force plate with their feet spread out to shoulder width, hand on their hips and eyes closed. The assessment will comprise of four trials (one practice trial) lasting 20 seconds in length and 20 seconds between trials. Center of pressure (COP) vector data along vertical (y) and horizontal (x) axes will be summed for the total path excursion length (cm) during each trial.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
CDC 4-Stage Balance Test (Postural stability) during daylong heat exposure
To assess postural stability, participants hold a tablet to their chest, then auditory cues guide participants through four consecutive stances, feet side by side, instep of one foot touching the big toe of the other foot, tandem stand with one foot in front of the other, heel touching toe, and stand on one foot. The balance assessment will be evaluated based on movement detected by an accelerometer integrated into the hardware of the tablet device (Sway Medical Inc).
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Memory recall (cognitive function) during daylong heat exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of memory recall. Participants complete both a delayed recall test and a working memory test.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Impulse control (cognitive function) during daylong heat exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of impulse control. Participants will be asked to respond to both "go" and "no-go" visual cues. In response to the "go" cue, participants will initiate a movement of the device.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Reaction time (cognitive function) during daylong heat exposure
Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of reaction time. Participants will be asked to initiate a movement of the device in response to a visual cue.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Orthostatic intolerance symptoms assessment during daylong heat exposure
Cumulative sum of scores on 6 questions asking participant to rank symptoms associated with orthostatic intolerance during the lying to standing tests. All symptoms scored on a scale from 0 (none) to 10 (worst possible) and include feelings of: (1) "dizziness, lightheadedness, feeling faint, or feeling like you might black out"; (2) "Problems with vision (blurring, seeing spots, tunnel vision, etc.)"; (3) "Weakness"; (4) "Fatigue"; (5) "Trouble concentrating"; and (6) "Head and neck discomfort".
Measured: End of 10 hour daylong heat exposure
Rate pressure product during daylong heat exposure
Rate pressure product, an index of myocardial work and strain, calculated as systolic blood pressure x heart rate.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Systolic Response to Standing From Supine during daylong heat exposure
Systolic blood pressure response to standing evaluated as the difference in blood pressure measured between the standing and supine. Standing systolic blood pressure will be taken as the lowest value of those measured after 60 and 120 seconds of standing. Systolic response to standing will be evaluated twice, during two lying-to-standing tests (separated by 10 min of supine rest).
Measured: End of 10 hour daylong heat exposure
Diastolic blood pressure during daylong heat exposure
Diastolic blood pressure measured in triplicate via automated oscillometry (~60 seconds between measures)
Measured: End of 10 hour daylong heat exposure
Systolic blood pressure during daylong heat exposure
Systolic blood pressure measured in triplicate via automated oscillometry (~60 seconds between measures)
Measured: End of 10 hour daylong heat exposure
Changes in plasma volume during daylong heat exposure
Change in plasma volume from baseline values calculated from duplicate measurements of hemoglobin and hematocrit at the start and end of each exposure using the technique by Dill and Costill
Measured: End of 10 hour daylong heat exposure
Fluid consumption during daylong heat exposure
Average hourly fluid consumption calculated by weighing participant water intake at the start and end of each hour of exposure (normalized to the exposure duration).
Measured: End of 10 hour daylong heat exposure
Fluid loss during daylong heat exposure
Body fluid loss calculated as a change in body weight from pre-exposure values (corrected for food intake and deification).
Measured: End of 10 hour daylong heat exposure
Arousal scale during daylong heat exposure
Felt arousal scale assessed via a visual analog scale ("How worked up are you?") ranging from "high arousal" to "low arousal".
Measured: End of 10 hour daylong heat exposure
Thermal sensation scale during daylong heat exposure
Thermal sensation assessed via a visual analog scale ranging from extremely hot to neutral (midpoint: hot).
Measured: End of 10 hour daylong heat exposure
Thirst sensation scale during daylong heat exposure
Thirst sensation scale assessed via a visual analog scale (9: very, very thirsty to 1: Not thirsty at all)
Measured: End of 10 hour daylong heat exposure
Thermal comfort scale during daylong heat exposure
Thermal comfort assessed via a visual analog scale ranging from extremely uncomfortable to extremely comfortable (midpoint: neutral).
Measured: End of 10 hour daylong heat exposure
Heart rate variability: SDNN during daylong heat exposure
Standard deviation of normal-to-normal R-wave to R-wave intervals (SDNN) measured during 5 minutes of paced breathing (15 breaths/min) with participants in the supine position. SDNN will be evaluated twice, during two paced breathing periods (separated by 4 min of supine rest).
Measured: At the start (hour 0) and end of daylong heat exposure (hour 10)
Heart rate variability: RMSSD during daylong heat exposure
Root mean squared standard deviation of normal-to-normal R-wave to R-wave intervals (RMSSD) measured during 5 minutes of paced breathing (15 breaths/min) with participants in the supine position. RMSSD will be evaluated twice, during two paced breathing periods (separated by 4 min of supine rest).
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Systolic Response to Standing From Supine during daylong heat exposure
Systolic blood pressure response to standing evaluated as the difference in blood pressure measured between the standing and supine. Standing systolic blood pressure will be taken as the lowest value of those measured after 60 and 120 seconds of standing. Systolic response to standing will be evaluated twice, during two lying-to-standing tests (separated by 10 min of supine rest). Assessed at the start and end of the 10 hour simulated heat wave exposure performed prior to and following the 7-day heat acclimation by warm-water immersion.
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Cardiac response to standing from supine (30:15 Ratio) during daylong heat exposure
Cardiac response to standing evaluated as the ratio between the highest R-wave to R-wave interval (lowest heart rate) measured at the 30th heart beat after standing from supine (+/- 5 beats) and the lowest R-wave to R-wave interval (highest heart rate) measured at the 15th heart beat after standing (+/- 5 beats). Cardiac response to standing will be evaluated twice, during two lying-to-standing tests (separated by 10 min of supine rest).
Measured: At the start (hour 0) and end of daylong heat exposure (hour 10)
Heat rate (AUC) during daylong heat exposure
Area under the curve (AUC) of heart rate during the 10 hour simulated heat wave exposure performed prior to and following the 7-day heat acclimation by warm-water immersion.
Measured: End of 10 hour daylong heat exposure
Heat rate (Peak) during daylong heat exposure
Peak Heart rate (15-min average) during the 10 hour simulated heat wave exposure performed prior to and following the 7-day heat acclimation by warm-water immersion.
Measured: End of 10 hour daylong heat exposure
Environmental Symptoms Questionnaire (ESQ)
Self-reported environmental reactions and medical symptomatology associated with prolonged heat exposure. The ESQ-IV is a validated 68-item, self-administered questionnaire that has been used successfully in identifying symptomatology during exposure to a wide variety of environmental conditions, including heat exposure [24, 25]. Participants are asked to assess and described "how you have been feeling today" by responding to each item using a 6-point Likert scale (0 = "Not at all", 1 = "Slight", 2 = "Somewhat", 3 = "Moderate", 4 = "Quite a bit", or 5 = "Extreme"). Total Symptom Score was calculated from this data by taking the sum of the intensity ratings from all 68 individual items using reverse scores for the three positive items from the list ("I Felt Good", "I Felt Alert", and "I Felt Wide Awake").
Measured: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Sleepiness during daylong heat exposure A
Karolinska sleepiness scale measures the subjective level of sleepiness at a particular time during the day on a scale of 1 to 10. 1 = extremely alert and 10 = extremely sleepy
Measured: End of 10 hour daylong heat exposure
Sleepiness during daylong heat exposure B
Stanford sleepiness scale consists of only one item, where participant must identify one of seven statements that best represents their level of perceived sleepiness. It employs a scale of 1 to 7 with 1 = feeling wide awake and 7 = sleep onset soon
Measured: End of 10 hour daylong heat exposure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Nov 2024
- Study start11 Nov 2024
- Primary completion18 May 2026
- Study completion18 May 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HyperthermiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Ottawa
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Glen P. Kenny, University of Ottawa
- Investigators
- Glen P Kenny, PhD, Principal investigator, University of Ottawa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06670365
- Sponsor's protocol ID
- HEPRU-2024-09-A
- Status last verified
- Jun 2026
- First submitted
- 29 Oct 2024
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Deidentified participant data will be made available with approved analysis plan and signed access agreement
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluating the Efficacy of Heat Acclimation by Warm Water Immersion for Mitigating Hyperthermia and Cardiovascular Demand in Older Adults During Indoor Overheating.
- ClinicalTrials.gov ID
- NCT06670365
- Acronym / sponsor ID
- HEPRU-2024-09-A
- Keywords
- thermoregulation, heat illness, heat acclimation, extreme heat events, women, indoor overheating, water immersion
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- University of OttawaUniversity, hospital or other
- Study start
- 11 Nov 2024 (actual)
- Primary completion
- 18 May 2026 (actual)
- Study completion
- 18 May 2026 (actual)
- First posted
- 1 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
As overheating in buildings is expected to increase as global warming continues, proactive measures to increase heat resiliency in heat-vulnerable older people are needed, especially for those without access to home cooling or reliable sources of electricity. While short-term heat acclimation through exercise in the heat has been shown to increase heat dissipation and decrease both the physical and mental stress imposed on individuals exposed to heat, such protocols are not tenable for older, sedentary adults. A recent report showed that seven consecutive days of warm-water immersion improved whole-body heat loss and reduced physiological strain as assessed during an exercise-heat stress in habitually active older men This represents a critical finding as an increase heat-loss capacity would serve as an important safeguard for older adults exposed to indoor overheating due to lack of air-conditioning. While this preliminary data highlights passive hot water immersion as a promising strategy for increasing heat-resilience in vulnerable adults, work is needed to confirm its efficacy in more "real-world" environments. Thus, this study aims to assess the effectiveness of a 7-day passive heating (warm-water immersion with core temperature clamped at ~38.5°C for the final 60 minutes) protocol in mitigating increases in thermal and cardiovascular strain in older females exposed to daylong (10-hours) indoor overheating (36°C, 45% relative humidity) prior to and following the passive heating intervention. Relative to males, females have a reduced heat loss capacity (~5%), which is driven by differences in the activation of heat loss responses (i.e., skin blood flow and sweating). Although there have been mixed findings with regards to the influence of sex as a mediating factor for heat-related mortality, some studies suggest that females are at a higher risk of heat-related mortality and morbidity compared to males, especially amongst older individuals (≥65 years). Notably, a greater proportion of older females died compared to their male counterparts during the 2021 Western Heat Dome. While the underlying causes for these differences remain unclear, greater cardiovascular strain may place females at higher mortality risk during extreme heat.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Daylong exposure to indoor overheating | Experimental | Other: Heat acclimation by warm-water immersionPrior to and following the warm-water immersion protocol, participants will undergo a 10-hour passive heat exposure where they will remain in a climate-controlled chamber regulated at 36°C and 45% humidity (temperatures experienced indoors during extreme heat events in North America). During this time they will remain seated with the exception of hourly 5-minute breaks to stretch. |
Who may qualify
- Ages
- 65 to 85 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (4 listed)
- Non-smoking.
- English or French speaking.
- Ability to provide informed consent.
- With or without a) chronic hypertension (elevated resting blood pressure; as defined by Heart and Stroke Canada and Hypertension Canada), b) type 2 diabetes as defined by Diabetes Canada, with at least 5 years having elapsed since time of diagnosis
Key exclusion criteria (6 listed)
- Episode(s) of severe hypoglycemia (requiring the assistance of another person) within the previous year, or inability to sense hypoglycemia (hypoglycemia unawareness).
- Serious complications related to your diabetes (gastroparesis, renal disease, uncontrolled hypertension, severe autonomic neuropathy).
- Uncontrolled hypertension - BP >150 mmHg systolic or >95 mmHg diastolic in a sitting position.
- Restrictions in physical activity due to disease (e.g. intermittent claudication, renal impairment, active proliferative retinopathy, unstable cardiac or pulmonary disease, disabling stroke, severe arthritis, etc.).
- Use of or changes in medication judged by the patient or investigators to make participation in this study inadvisable.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Heat acclimation by warm-water immersionParticipants will be immersed in a whirlpool tub to the shoulder level in a circulated water bath maintained at ~40°C until their core temperature achieves a steady-state of 38.5°C for 60 minutes. The warm-water immersion protocol will be repeated for 6 more consecutive days. | Other | Daylong exposure to indoor overheating |
Primary outcome
Core temperature (Peak) during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Peak rectal temperature (15 min average) during exposure. Rectal temperature is measured continuously throughout the 10 hours of the simulated heat wave performed prior to and following the 7-day heat acclimation by warm-water immersion.
29 secondary outcomes
Muscle oxygen during battery of cardiovascular, cognition and postural stability tests during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Profiles of Mood States (POMS) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Core temperature (AUC) during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
BTrackS Balance Assessment (Postural stability) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
CDC 4-Stage Balance Test (Postural stability) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Memory recall (cognitive function) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Impulse control (cognitive function) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Reaction time (cognitive function) during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Orthostatic intolerance symptoms assessment during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Rate pressure product during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Systolic Response to Standing From Supine during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Diastolic blood pressure during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Systolic blood pressure during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Changes in plasma volume during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Fluid consumption during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Fluid loss during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Arousal scale during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Thermal sensation scale during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Thirst sensation scale during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Thermal comfort scale during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Heart rate variability: SDNN during daylong heat exposure
Time frame: At the start (hour 0) and end of daylong heat exposure (hour 10)
Heart rate variability: RMSSD during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Systolic Response to Standing From Supine during daylong heat exposure
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Cardiac response to standing from supine (30:15 Ratio) during daylong heat exposure
Time frame: At the start (hour 0) and end of daylong heat exposure (hour 10)
Heat rate (AUC) during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Heat rate (Peak) during daylong heat exposure
Time frame: End of 10 hour daylong heat exposure
Environmental Symptoms Questionnaire (ESQ)
Time frame: At the start (hour 0) and end of the daylong heat exposure (hour 10)
Sleepiness during daylong heat exposure A
Time frame: End of 10 hour daylong heat exposure
Sleepiness during daylong heat exposure B
Time frame: End of 10 hour daylong heat exposure
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Individual participant dataSharing planned: Yes. Deidentified participant data will be made available with approved analysis plan and signed access agreement
Related trials for Hyperthermia
Recruiting
Assessment of Communication Interventions on Vaccination Knowledge and Acceptance
Vaccination Knowledge and Acceptance, Informed Vaccine-decision Making
RecruitingObservational study
Natural History of Trisomy 8-Associated Autoinflammatory Disease (TRIAD) and Related Disorders
Trisomy 8 Mosaicism, Trisomy 8 Associated Autoinflammatory Disease
RecruitingObservational study
Familial Mediterranean Fever and Related Disorders: Genetics and Disease Characteristics
Familial Mediterranean Fever (FMF), Autoinflammation
RecruitingPhase 1
Individual Response to Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Treatment of Peritoneal Carcinomatosis From Peritoneal Mesothelioma or Atypical Mesothelial Proliferation or From Ovarian, Colorectal, or Appendiceal Histologies
Peritoneal Mesothelioma, Peritoneal Carcinomatosis
Recruiting
Recovery After Fatigue in Young Athletes: Comparison Between TECAR Therapy and Cycle Ergometer"
Muscle Fatigue, Healthy Adult
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Glen P Kenny, PhD principal investigator
University of Ottawa
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heat acclimation by warm-water immersion in people with Hyperthermia and Thermoregulation, run by University of Ottawa at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Core temperature (Peak) during daylong heat exposure (time frame: End of 10 hour daylong heat exposure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2026.