Core TemperatureNCT06956430
Mitigating Heat Stress Among Rickshaw Drivers in Bangladesh
A study testing Battery-powered rickshaw in people with Core Temperature and Telomere Length, Mean Leukocyte, run by University of California, Berkeley.
Trial summary
The goal of the experimental study is to understand the impact of heat stress on core temperature and telomere length. Investigators will recruit rickshaw drivers who use manual power to push their rickshaws and randomly assign half of them to receive battery-powered rickshaws to use for four months. Read more about this study
- Who is it for?
- Ages 40 years and older, men only
- Conditions the study is for
- Core Temperature, Telomere Length, Mean Leukocyte, Kidney Function Issue
- What is being tested?
- Battery-powered rickshaw
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- No sites listed yet
- Study dates
- 1 Jun 2025to 31 Dec 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 40 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Reports driving a manual rickshaw at least five days per week for at least 8 hours per day for the past 12 months
Who cannot join
- Reports driving a battery-powered rickshaw in the past 12 months
- Has hypertension, as measured by our study staff
- Has diabetes, as measured by our staff
- Reports diagnosis with cardiovascular disease / chronic cardiac condition
- Reports diagnosis with respiratory disease / chronic respiratory condition
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: How Does Heat Stress Affect Telomere Length? A Pilot Randomized Controlled Trial in Urban Bangladesh
The goal of the experimental study is to understand the impact of heat stress on core temperature and telomere length. Investigators will recruit rickshaw drivers who use manual power to push their rickshaws and randomly assign half of them to receive battery-powered rickshaws to use for four months. Investigators will assess how this change impacts their core body temperature while they work, the length of their telomeres (caps on the end of DNA that are associated with aging), and kidney function.
Read the detailed description
Personal exposure to heat may be elevated above ambient temperatures if an individual is very active (which generates metabolic heat) or wears clothing that prevents cooling. Age can influence the consequences of heat stress. Older adults are at elevated risk of adverse impacts from heat stress due to their reduced ability to dissipate heat. Heat stress is particularly high among outdoor workers. South Asia has millions of bicycle rickshaw drivers, who use their muscles or battery power to pull hundreds of pounds of passengers and goods on modified bicycles. When manual rickshaw drivers rest to cool off, they reduce their already meager income. Heat stress not only threatens their livelihoods and thereby their right to an adequate standard of living but also their right to work, given that they have few employable skills other than manual labor. South Asia faces the greatest current and predicted loss in disability-adjusted life years due to heat stress, and heat stress is particularly strong in informal settlements. As such, the investigators plan to conduct this study in Dhaka, Bangladesh. The overall hypothesis is that driving a battery-powered rickshaw will reduce heat strain. The investigators will evaluate the impact of driving a battery-powered rickshaw on core temperature (primary outcome), telomere length, kidney function, heart rate, heart rate variability, sleep quality, self-reported thermal comfort, mental health, wellness, and fatigue (secondary outcomes).
- Being tested
- Battery-powered rickshaw
- Keywords
- heat stress, heat strain, rickshaw, heart rate, heart rate variability, sleep quality, Bangladesh
- Medical subject headings
- Heat Stress Disorders, Sleep Initiation and Maintenance Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Battery-powered rickshawDevice
A battery-powered rickshaw is a rickshaw where the wheels are turned by a small electric motors powered by a battery.
| Study group | Role | What they receive |
|---|---|---|
| Manual rickshaw | No intervention | Rickshaw drivers will use manually powered rickshaws |
| Battery-powered rickshaw | Experimental | Rickshaw drivers will use battery-powered rickshaws Receives: Device: Battery-powered rickshaw |
What is being measured
The primary outcome is the main question the study is designed to answer.
Core temperature
Minutes per day that core temperature is >40C, where fewer minutes per day is better
Measured: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Secondary outcomes (5)
Relative Leucocyte Telomere Length
Change in Relative Leucocyte Telomere Length measured by PCR, where a smaller reduction in length is better
Measured: 0 (pre-intervention) and 16 weeks post-intervention
Kidney function
kidney function, as measured by a the neutrophil gelatinase-associated lipocalin (NGAL) value in urine samples, where a lower score is better
Measured: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Heart rate
resting heart rate (bpm), where a lower heart rate is better
Measured: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Heart rate variability
resting heart rate (bpm) variability, where higher variability is better
Measured: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Sleep quality
Self-reported sleep quality and number of minutes in REM, as recorded by a fitness watch, where more minutes in REM is better
Measured: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 May 2025
- Study start1 Jun 2025 (estimated)
- Primary completion31 Oct 2025 (estimated)
- Study completion31 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Core TemperatureStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- Stepped-wedge randomized controlled trial
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Berkeley
- Sponsor type
- University, hospital or other
- Collaborators
- International Centre for Diarrhoeal Disease Research, Bangladesh, North South University
- Responsible party
- Sponsor
- Investigators
- Laura Kwong, PhD, Principal investigator, University of California, Berkeley
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06956430
- Sponsor's protocol ID
- 2023-05-16316
- Status last verified
- May 2025
- First submitted
- 25 Apr 2025
- Last updated
- 21 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We will post de-identified participant data on our OSF repository (https://osf.io/sd285/)
Study at a glance
From the registry record, last updated by the sponsor on 21 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- How Does Heat Stress Affect Telomere Length? A Pilot Randomized Controlled Trial in Urban Bangladesh
- ClinicalTrials.gov ID
- NCT06956430
- Acronym / sponsor ID
- 2023-05-16316
- Keywords
- heat stress, heat strain, rickshaw, heart rate, heart rate variability, sleep quality, Bangladesh
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- University of California, BerkeleyUniversity, hospital or other
- Collaborators
- International Centre for Diarrhoeal Disease Research, Bangladesh, North South University
- Study start
- 1 Jun 2025 (estimated)
- Primary completion
- 31 Oct 2025 (estimated)
- Study completion
- 31 Dec 2025 (estimated)
- First posted
- 4 May 2025 (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.
The goal of the experimental study is to understand the impact of heat stress on core temperature and telomere length. Investigators will recruit rickshaw drivers who use manual power to push their rickshaws and randomly assign half of them to receive battery-powered rickshaws to use for four months. Investigators will assess how this change impacts their core body temperature while they work, the length of their telomeres (caps on the end of DNA that are associated with aging), and kidney function.
Detailed description
Personal exposure to heat may be elevated above ambient temperatures if an individual is very active (which generates metabolic heat) or wears clothing that prevents cooling. Age can influence the consequences of heat stress. Older adults are at elevated risk of adverse impacts from heat stress due to their reduced ability to dissipate heat. Heat stress is particularly high among outdoor workers. South Asia has millions of bicycle rickshaw drivers, who use their muscles or battery power to pull hundreds of pounds of passengers and goods on modified bicycles. When manual rickshaw drivers rest to cool off, they reduce their already meager income. Heat stress not only threatens their livelihoods and thereby their right to an adequate standard of living but also their right to work, given that they have few employable skills other than manual labor. South Asia faces the greatest current and predicted loss in disability-adjusted life years due to heat stress, and heat stress is particularly strong in informal settlements. As such, the investigators plan to conduct this study in Dhaka, Bangladesh. The overall hypothesis is that driving a battery-powered rickshaw will reduce heat strain. The investigators will evaluate the impact of driving a battery-powered rickshaw on core temperature (primary outcome), telomere length, kidney function, heart rate, heart rate variability, sleep quality, self-reported thermal comfort, mental health, wellness, and fatigue (secondary outcomes).
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Stepped-wedge randomized controlled trial
| Arm | Type | Receives |
|---|---|---|
| Manual rickshaw | No intervention | –Rickshaw drivers will use manually powered rickshaws |
| Battery-powered rickshaw | Experimental | Device: Battery-powered rickshawRickshaw drivers will use battery-powered rickshaws |
Who may qualify
- Ages
- 40 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Reports driving a manual rickshaw at least five days per week for at least 8 hours per day for the past 12 months
Key exclusion criteria (5 listed)
- Reports driving a battery-powered rickshaw in the past 12 months
- Has hypertension, as measured by our study staff
- Has diabetes, as measured by our staff
- Reports diagnosis with cardiovascular disease / chronic cardiac condition
- Reports diagnosis with respiratory disease / chronic respiratory condition
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 |
|---|---|---|
| Battery-powered rickshawA battery-powered rickshaw is a rickshaw where the wheels are turned by a small electric motors powered by a battery. | Device | Battery-powered rickshaw |
Primary outcome
Core temperature
Time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Minutes per day that core temperature is >40C, where fewer minutes per day is better
5 secondary outcomes
Relative Leucocyte Telomere Length
Time frame: 0 (pre-intervention) and 16 weeks post-intervention
Kidney function
Time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Heart rate
Time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Heart rate variability
Time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Sleep quality
Time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 May 2025.
- Individual participant dataSharing planned: Yes. We will post de-identified participant data on our OSF repository (https://osf.io/sd285/)
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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.
Laura Kwong, PhD principal investigator
University of California, Berkeley
Questions about this trial
What is this clinical trial studying?
A study testing Battery-powered rickshaw in people with Core Temperature and Telomere Length, Mean Leukocyte, run by University of California, Berkeley.
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 1 inclusion and 5 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: opening soon, as of the sponsor's last update on 21 May 2025. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Laura Kwong, PhD (16504609593, lakwong@berkeley.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Core temperature (time frame: 0 (pre-intervention) and 2, 4, 6, 8, 10, 12, 14, 16 weeks post-intervention). 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 21 May 2025.