Non-invasive Prediction of Thermal Strain in Healthy Male Adults

Single-centre Experimental Evaluation of Methods for Reliable Non-invasive Prediction of Thermal Strain in Healthy Male Adults

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04650776

Acronym

HUMONHEAT

Enrollment

Registered

2020-12-03

Start date

2017-09-01

Completion date

2018-04-30

Last updated

2020-12-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Heat Stress

Brief summary

This is primarily an experimental study investigating methods of temperature measurement / heat strain detection. In the calibration study, there are different skin temperature sensor types, and in the prediction study there are different methods for determining heat strain, including conventional methods (rectal, gastro-intestinal), the development of a prediction model, and an index based on heart rate variability.

Interventions

OTHERHeat strain

The experimental procedure comprised 15 min baseline seated rest (23.2 ± 0.3°C, 24.5 ± 1.6% relative humidity), followed by 15 min seated rest and cycling in a climatic chamber (35.4 ± 0.2◦C, 56.5 ± 3.9% relative humidity; to +1.5◦C or maximally 38.5°C rectal temperature, duration 20-60 min), with a final 30 min seated rest outside the chamber.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

SCREENING

Masking

NONE

Eligibility

Sex/Gender

MALE

Age

18 Years to 45 Years

Healthy volunteers

Yes

Inclusion criteria

* Apparently healthy males * aged 18-45 y * regularly participate in sport, exercise, or equivalent physical activity on a weekly basis.

Exclusion criteria

* Known injuries or illnesses that may affect safe participation. These include injuries or illnesses involving (but not limited to): * cardiovascular, renal, or gastrointestinal tract * heat or exercise intolerance * acute infections, * immunological diseases (including asthma) * psychiatric disorders. * Participants must not be currently or previously on cardiovascular-related medication and must not be taking psychotropic medication (last 60 days).

Design outcomes

Primary

Measure	Time frame	Description
Core body temperature	90 minutes	Rectal core body temperature (unit of measure is degree celsius °C)
Predicted core body temperature	90 minutes	Estimated core body temperature (°C) from selected non-invasive measurements: applying a multiple linear regression model several predictive parameters, including skin temperature at different body sites, heat flux at different body sites, and heart rate will be combined to achieve one reported temperature value (°C)
ECG-based heat strain index	90 minutes	ECG-based index of heat strain derived from heart rate variability

Countries

Switzerland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026