Body Temperature ChangesNCT07781605
Ambient Temperature and Thermoregulation During Exercise in Children and Youth
A study testing Exercise at 22°C, Exercise at 26°C and Exercise at 31°C in people with Body Temperature Changes and Heat Stress, run by University of Ottawa at 1 site in Canada.
Trial summary
Little is known about how children and youth regulate body temperature during exercise across different environmental temperatures compared with young adults, including whether differences in whole-body heat exchange contribute to their responses. Read more about this study
- Who is it for?
- Ages 9 to 25 yearsHealthy volunteers can take part
- Conditions the study is for
- Body Temperature Changes, Heat Stress, Child Development
- What is being tested?
- Exercise at 22°C, Exercise at 26°C and Exercise at 31°C
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteCanada
- Study dates
- 19 Jul 2026to 30 Jun 2027
- 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 9 to 25 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Healthy male or female.
- Aged 9-16 years or 20-25 years.
- Habitually active, defined as participating in regular physical activity at least 3 times per week for at least 20 minutes per session over the previous 6 months.
- Able to understand and communicate in English or French.
- For participants younger than 18 years, written parental or guardian consent and participant assent are required.
Who cannot join
- Acute illness at the time of testing (e.g., cold, flu, or infection).
- History of a chronic medical condition that may affect thermoregulation, cardiovascular function, or exercise capacity (e.g., cardiovascular disease, metabolic disorders, respiratory disease including asthma requiring regular medication, or neurological disorders).
- Use of medications known to affect thermoregulation, hydration status, or cardiovascular responses.
- History of heat-related illness (e.g., heat exhaustion or heat stroke).
- Digestive abnormalities or gastrointestinal conditions that may contraindicate ingestion of a telemetry pill.
- Any condition that, in the opinion of the investigators, would compromise participant safety or the integrity of the data.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
University of Ottawa
Ottawa, Ontario, K1N 6N5
Glen P Kenny, PhD, 613-562-5800 ext. 4282, gkenny@uottawa.ca
About this study
Official title: Ambient Temperature and Thermoregulation During Moderate-Intensity Exercise in Children and Youth
Little is known about how children and youth regulate body temperature during exercise across different environmental temperatures compared with young adults, including whether differences in whole-body heat exchange contribute to their responses. The goal of this clinical trial is to determine how ambient temperature affects thermoregulation during exercise in boys and girls aged 9-16 years compared with young adult men and women aged 20-25 years. Participants will complete four study visits at ambient temperatures of 22°C (Celsius; 72°F, Fahrenheit), 26°C (79°F), 31°C (88°F), and 36°C (97°F), while exercising at the same moderate-intensity metabolic heat production of 160 W/m² (W = watts, m = meters). During each visit, participants will complete four 15-minute periods of exercise (exercise bouts 1, 2, 3 and 4 respectively) separated by 15-minute rest periods. Testing will be performed in a whole-body air calorimeter, a specialized chamber that precisely measures heat lost through evaporation and dry heat exchange and the amount of heat stored in the body. These measurements, together with core temperature and heart rate, will allow researchers to determine how increasing ambient temperature affects the body's ability to lose heat and whether these responses differ between children and youth and young adults.
- Being tested
- Exercise at 22°C, Exercise at 26°C, Exercise at 31°C, Exercise at 36°C
- Keywords
- Thermoregulation, Heat loss, Heat tolerance, Heat strain, Physical activity
- Medical subject headings
- Body Temperature Changes, Heat Stress Disorders, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exercise at 22°COther
Participants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 22°C (72°F).
Exercise at 26°COther
Participants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 26°C (79°F).
Exercise at 31°COther
Participants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 31°C (88°F).
Exercise at 36°COther
Participants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 36°C (97°F).
| Study group | Role | What they receive |
|---|---|---|
| Exercise at 22°C | Experimental | Participants will complete intermittent moderate-intensity exercise at an ambient temperature of 22°C (celsius; 72°F, fahrenheit). Exercise will be performed at a metabolic heat production of 160 W/m² (W = watts, m = meters) and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. Receives: Other: Exercise at 22°C |
| Exercise at 26°C | Experimental | Participants will complete intermittent moderate-intensity exercise at an ambient temperature of 26°C (79°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. Receives: Other: Exercise at 26°C |
| Exercise at 31°C | Experimental | Participants will complete intermittent moderate-intensity exercise at an ambient temperature of 31°C (88°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. Receives: Other: Exercise at 31°C |
| Exercise at 36°C | Experimental | Participants will complete intermittent moderate-intensity exercise at an ambient temperature of 36°C (97°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. Receives: Other: Exercise at 36°C |
What is being measured
The primary outcome is the main question the study is designed to answer.
Core temperature
Core temperature indexed by visceral (telemetry pill) temperature
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Secondary outcomes (8)
Evaporative heat loss
Evaporative heat loss as assessed using a direct air calorimeter
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Dry heat loss
Dry heat loss as assessed using a direct air calorimeter
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Whole-body total heat loss
Total heat loss (evaporative + dry) as assessed using a direct air calorimeter
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Body heat storage
Heat stored in the body for each of the exercise bouts
Measured: Change from start to end of exercise for each of the four 15 minutes exercise bouts
Skin temperature
Skin temperature measured at 8-sites (forehead, chest, scapula, upper arm, forearm, hand, thigh, calf) with mean value calculated as weighted values of 8 sites - forehead 7%, chest 17.5%, scapula 17.5%, upper arm 7%, forearm 7%, hand 5%, thigh 19%, and calf 20%.
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Change in skin temperature
Skin temperature measured at 8-sites (forehead, chest, scapula, upper arm, forearm, hand, thigh, calf) with mean value calculated as weighted values of 8 sites - forehead 7%, chest 17.5%, scapula 17.5%, upper arm 7%, forearm 7%, hand 5%, thigh 19%, and calf 20%.
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Heart rate
Heart rate measured continuously with chest-band telemetric device
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Thermal sensation
Thermal sensation will be assessed using the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 7-point scale ("0=neutral to 7=extremely hot")
Measured: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Aug 2026
- Study start19 Jul 2026
- Primary completion30 Apr 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Body Temperature ChangesStudies 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
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Ottawa
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Glen P. Kenny, University of Ottawa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07781605
- Sponsor's protocol ID
- HEPRU-2026-08B
- Status last verified
- Aug 2026
- First submitted
- 18 Aug 2026
- Last updated
- 24 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ambient Temperature and Thermoregulation During Moderate-Intensity Exercise in Children and Youth
- ClinicalTrials.gov ID
- NCT07781605
- Acronym / sponsor ID
- HEPRU-2026-08B
- Keywords
- Thermoregulation, Heat loss, Heat tolerance, Heat strain, Physical activity
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- University of OttawaUniversity, hospital or other
- Study start
- 19 Jul 2026 (actual)
- Primary completion
- 30 Apr 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 24 Aug 2026 (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.
Little is known about how children and youth regulate body temperature during exercise across different environmental temperatures compared with young adults, including whether differences in whole-body heat exchange contribute to their responses. The goal of this clinical trial is to determine how ambient temperature affects thermoregulation during exercise in boys and girls aged 9-16 years compared with young adult men and women aged 20-25 years. Participants will complete four study visits at ambient temperatures of 22°C (Celsius; 72°F, Fahrenheit), 26°C (79°F), 31°C (88°F), and 36°C (97°F), while exercising at the same moderate-intensity metabolic heat production of 160 W/m² (W = watts, m = meters). During each visit, participants will complete four 15-minute periods of exercise (exercise bouts 1, 2, 3 and 4 respectively) separated by 15-minute rest periods. Testing will be performed in a whole-body air calorimeter, a specialized chamber that precisely measures heat lost through evaporation and dry heat exchange and the amount of heat stored in the body. These measurements, together with core temperature and heart rate, will allow researchers to determine how increasing ambient temperature affects the body's ability to lose heat and whether these responses differ between children and youth and young adults.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Exercise at 22°C | Experimental | Other: Exercise at 22°CParticipants will complete intermittent moderate-intensity exercise at an ambient temperature of 22°C (celsius; 72°F, fahrenheit). Exercise will be performed at a metabolic heat production of 160 W/m² (W = watts, m = meters) and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. |
| Exercise at 26°C | Experimental | Other: Exercise at 26°CParticipants will complete intermittent moderate-intensity exercise at an ambient temperature of 26°C (79°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. |
| Exercise at 31°C | Experimental | Other: Exercise at 31°CParticipants will complete intermittent moderate-intensity exercise at an ambient temperature of 31°C (88°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. |
| Exercise at 36°C | Experimental | Other: Exercise at 36°CParticipants will complete intermittent moderate-intensity exercise at an ambient temperature of 36°C (97°F). Exercise will be performed at a metabolic heat production of 160 W/m² and will consist of four 15-minute exercise periods separated by 15-minute rest periods. Exercise workload will be individually adjusted to achieve the prescribed metabolic heat production. |
Who may qualify
- Ages
- 9 to 25 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- Healthy male or female.
- Aged 9-16 years or 20-25 years.
- Habitually active, defined as participating in regular physical activity at least 3 times per week for at least 20 minutes per session over the previous 6 months.
- Able to understand and communicate in English or French.
- For participants younger than 18 years, written parental or guardian consent and participant assent are required.
Key exclusion criteria (6 listed)
- Acute illness at the time of testing (e.g., cold, flu, or infection).
- History of a chronic medical condition that may affect thermoregulation, cardiovascular function, or exercise capacity (e.g., cardiovascular disease, metabolic disorders, respiratory disease including asthma requiring regular medication, or neurological disorders).
- Use of medications known to affect thermoregulation, hydration status, or cardiovascular responses.
- History of heat-related illness (e.g., heat exhaustion or heat stroke).
- Digestive abnormalities or gastrointestinal conditions that may contraindicate ingestion of a telemetry pill.
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 |
|---|---|---|
| Exercise at 22°CParticipants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 22°C (72°F). | Other | Exercise at 22°C |
| Exercise at 26°CParticipants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 26°C (79°F). | Other | Exercise at 26°C |
| Exercise at 31°CParticipants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 31°C (88°F). | Other | Exercise at 31°C |
| Exercise at 36°CParticipants complete intermittent exercise at a metabolic heat production of 160 W/m² in an ambient temperature of 36°C (97°F). | Other | Exercise at 36°C |
Primary outcome
Core temperature
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Core temperature indexed by visceral (telemetry pill) temperature
8 secondary outcomes
Evaporative heat loss
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Dry heat loss
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Whole-body total heat loss
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Body heat storage
Time frame: Change from start to end of exercise for each of the four 15 minutes exercise bouts
Skin temperature
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Change in skin temperature
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Heart rate
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
Thermal sensation
Time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)
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 24 Aug 2026.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Exercise at 22°C, Exercise at 26°C and Exercise at 31°C in people with Body Temperature Changes and Heat Stress, 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 5 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: looking for participants now, as of the sponsor's last update on 24 Aug 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?
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 Glen P Kenny, PhD (6135625800 ext. 4282, gkenny@uottawa.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Core temperature (time frame: End of each of the four 15 minutes exercise bouts (average of last 5 minutes)). 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 24 Aug 2026.