An interventional study of Heat acclimation in Body Temperature Changes, Heat Exposure and Heat Stress, sponsored by Maastricht University Medical Center. Not yet recruiting. Open to participants aged 60 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-04-29.
Sponsored by Maastricht University Medical Center · Not applicable, Interventional, and Prevention
As the ongoing progression of climate change exposes individuals to elevated temperatures and an escalating frequency of extreme heat events, the risk of more intense and prolonged heat waves raises significant concerns for public health, particularly among vulnerable populations. The physiological response to acute heat stress involves involuntary thermolytic reactions that may strain the cardiovascular system, especially in individuals with pre-existing vulnerabilities. Heat acclimation has been identified as a potential strategy to enhance thermoregulation and mitigate the adverse effects of heat stress. While existing research primarily focuses on athletes and military, this study aims to investigate the impact of a practical heat acclimation strategy, combining passive and active heat exposure, on thermophysiological, cardiovascular and metabolic parameters in healthy overweight adults. The study targets a population at increased risk for heat-related complications, seeking to provide realistic guidelines for broader application when a heat wave appears on the weather forecast.
A non-randomized, within-subject experimental trial will be conducted. The complete study will consist of a screening day, a control week, a heat acclimation week, 3 heat stress test (HST) and meal-test (MT) days (t = -7, 0, and 8 (days)). To avoid a confounding effect of seasonal thermal differences and achieve maximal methodological quality, the study will be performed in the shortest possible timeframe for each participant. Given the seasonal fluctuations in NL, transitioning from April (\~7oC) to June (\~20oC), a crossover design is not applicable as a washout period of approximately 2 months would be needed and the measurements would likely take place in different climatic outdoor conditions. In total, 12 healthy male and female participants will be included in the study. During the no-intervention week (week 1), participants will be asked to continue their normal life at home, without being present at the university. In addition, during week 1, participants will be asked to wear a temperature sensor on their clothing to measure the environment temperature they are exposed to at home. Thereafter, on the intervention week (week 2), participants will be exposed to increasing elevated temperatures and undergo 30 min of low-to-moderate intensity cycling in the heated laboratory room for 7 days. The temperature settings are derived from past heat waves in the Netherlands, ensuring a realistic representation. The low exercise intensity is selected to be accessible to the majority of individuals within the target population. The HST-MT will be conducted on the first visit after the screening to serve as baseline measurements. The same tests will also be repeated before and after the heat acclimation week to determine the physiological response to increasing ambient temperatures. All measurements will take place in the Metabolic Research Unit of Maastricht University (MRUM), the Netherlands.
256 studies on the registry are indexed under Hyperthermia; 73 are open to participants now.
This study's planned enrollment of 12 is below the median of 40 across 232 interventional studies indexed under Hyperthermia.
Browse Hyperthermia studies →Maastricht University Medical Center is the lead sponsor of 853 studies on the registry; 114 are open to participants now.
Compared within Hyperthermia, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Body Temperature Changes. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Passive heat exposure (29-35ºC; 6h/day for 7 days) in combination with 30min/day low-to-moderate intensity cycling.
Other: Heat acclimation
Daily repeated heat exposure to assess the effects of combined passive and active heat acclimation
Core temperature
thermophysiological parameters (ºC)
Time frame: 1 week of heat acclimation
Skin temperature
thermophysiological parameters (ºC)
Time frame: 1 week of heat acclimation
Sweat rate
thermophysiological parameters (mL/min)
Time frame: 1 week of heat acclimation
Heart rate
cardiovascular parameters (bpm)
Time frame: 1 week of heat acclimation
Blood pressure
cardiovascular parameters (mmHg)
Time frame: 1 week of heat acclimation
Skin blood flow
cardiovascular parameters (mL/min)
Time frame: 1 week of heat acclimation
Energy expenditure
Metabolic parameters (kJ/min)
Time frame: 1 week of heat acclimation
Substrate oxidation
glucose and fat oxidation (umol/kg/min)
Time frame: 1 week of heat acclimation
Plasma metabolites
Plasma glucose, insulin, free-fatty acids, triglycerides, total cholesterol (mmol/L)
Time frame: 1 week of heat acclimation
Brain blood flow
additional cardiovascular parameters (mL/min)
Time frame: 1 week of heat acclimation
Flow-mediated dilation
endothelial function, (mm)
Time frame: 1 week of heat acclimation
No study locations are listed for this record.
Plan to share: No
Start is estimated for May 2024; primary completion for Dec 2024, 7 months later.
Of 103 non-industry interventional studies with no phase under Hyperthermia, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 30. This study's planned 7 months is below that.
Counting every sponsor, half of 108 studies reached it within 18 months; a quarter within 7 and three quarters within 30.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Apr 2024. You cannot join it, but the record below documents what was studied.
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