How the body responds to severe heat during high-risk military activities

Physiological Responses to Heat Stress During High-risk Events

Observational United States Army Research Institute of Environmental Medicine · NCT06907225

This study will test whether blood and other measurements taken before, after, and at follow-up can identify markers of exertional heat stroke and recovery in military personnel who train in hot conditions.

Quick facts

Study typeObservational
Enrollment150 (estimated)
Ages18 Years and up
SexAll
SponsorUnited States Army Research Institute of Environmental Medicine Federal
Locations2 sites (Fort Novosel, Alabama and 1 other locations)
Trial IDNCT06907225 on ClinicalTrials.gov

What this trial studies

This observational field study will enroll active service members participating in routine training at Fort Novosel and during a field study at Fort Jackson to collect pre-event, immediate post-event, and follow-up physiological and biomarker data. Investigators will measure core temperature, blood biomarkers of cardiac, kidney, muscle, and liver injury, and other clinical measures without altering participants' training or treatment. Because exertional heat stroke cannot be safely induced in the lab, the study relies on prospective data collection around real training events where heat illness may occur. The goal is to define biomarker patterns that relate to risk, acute injury, and recovery to inform safer return-to-duty decisions.

Who should consider this trial

Good fit: Ideal candidates are active, Reserve, or National Guard service members aged 18 or older who are currently participating in running or other training at the study locations and who do not meet any exclusion criteria such as pregnancy or recent blood donation.

Not a fit: Civilians, non-deployed personnel not participating in relevant training, pregnant individuals, and people with excluded medical conditions or recent blood donation are unlikely to benefit directly from participation.

Why it matters

Potential benefit: If successful, the study could identify biomarkers that help clinicians predict risk, track organ injury, and make safer return-to-duty decisions after exertional heat stroke.

How similar studies have performed: Prior prospective field investigations have provided useful clinical insights, but reliably identifying specific biomarkers tied to exertional heat stroke risk and recovery remains largely unproven.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Individuals (to include cis- and transgender males and females and nonbinary) 18 years of age or greater
* Current military service (active, Reserve, or National Guard)
* Currently participating in training

Exclusion Criteria:

* Females who are pregnant
* Any individual currently on a physical profile that restricts running or foot marching
* History of obstructive disease of the gastrointestinal tract including (but not limited to) diverticulosis, diverticulitis and inflammatory bowel disease, peptic ulcer disease, Crohn's disease, ulcerative colitis.
* Scheduled MRI within 2 weeks after core temp pill ingestion
* Known allergies to skin adhesive
* Blood donation in the past 8 weeks

Where this trial is running

Fort Novosel, Alabama and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions ThermoregulationHeat illness
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.