Comparing Exertional Heat Illness Risk Factors Between Patients and Controls

University of Portsmouth

Status: Completed

Conditions: Exertional Heat Illness

Treatments: Other: Heat Tolerance Assessment

Study type: Observational

Funder types: Other

Identifiers

NCT05303142

209321

Details and patient eligibility

About

The arduous nature of military training and operations require personnel to encounter high heat load, e.g., during intense physical exertion, particularly in the heat. These conditions reduce operational effectiveness and expose personnel to a risk of incapacitation and death from exertional heat illness (EHI). The primary aim of this study is to compare putative 'chronic' EHI risk factors between a cohort who have suffered a history of EHI and a control cohort with no EHI history. The secondary aim is to examine the influence of these EHI risk factors on thermoregulation during a standard heat tolerance assessment.

Full description

Military training and operations present a risk of incapacitation and death from Exertional Heat Illness (EHI). However, widely accepted EHI risk factors are absent in almost half of all United Kingdom (UK) military EHI cases, indicating that a significant number of EHI cases in military personnel involve alternative risk factors. Risk factors for EHI can been classified along a spectrum ranging from acute (e.g. recent poor sleep) to chronic (e.g. low fitness), with the role of chronic risk factors supported by the observation that individuals who have suffered an EHI are at a substantially increased risk of subsequent EHI. The primary aim of this study is to compare putative 'chronic' EHI risk factors (e.g. composition of gastrointestinal (GI) microbiome, infection and inflammation, trait-like psychological factors) between a cohort who have suffered a history of EHI and a control cohort with no EHI history. The secondary aim is to examine the influence of these EHI risk factors on thermoregulation during a standard heat tolerance assessment.

Enrollment: 95 patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria:

Individuals with a history of EHI:

• Previous EHI episode
• Normal resting ECG
• Male or female
• 18 - 40 years

Control participants:

• No previous history of EHI
• Normal resting ECG
• Male or female
• 18 - 40 years

Trial design

95 participants in 2 patient groups

Individuals with a history of EHI

Description:

Service personnel who have a history of EHI.

Treatment:

Other: Heat Tolerance Assessment

Control participants without a history of EHI

Description:

Matched control participants with no history of EHI. They will be matched to the experimental group for parameters that are known to influence thermoregulatory responses to exercise heat-stress. 1. Relative aerobic fitness (V̇O2max; ml∙kg-1∙min-1) 2. Body mass (kg) 3. Body surface area (m2) 4. Age 5. Sex

Treatment:

Other: Heat Tolerance Assessment