The overall goal of this project is to identify a work/rest cycle that allows for faster mission completion needed in emergency situations, compared to current Army heat guidance, while mitigating heat strain and neuromuscular fatigue. This project will determine the trade-off between faster mission completion and risk of heat strain and physical performance decrements. Completion of this project will allow military leaders to make informed decisions by understanding the impact of their choices on the magnitude of physical performance decrements and expected heat casualties, setting up hot weather missions for success.

Inclusion Criteria:

• Healthy individuals
• Physically active

Exclusion Criteria:

• History of cardiovascular, metabolic (such as clinical thyroid disease), respiratory, neural, or renal disease
• Hypertensive (systolic blood pressure > 139 mmHg, diastolic blood pressure > 89 mmHg) or tachycardic (heart rate > 100 bpm) during the screening visit
• Taking medications or supplements known to effect physiologic responses to exercise or thermoregulation (e.g., beta blockers, omega-3 fatty acids, statins, aspirin)
• Tobacco or nicotine use currently or in the past six months
• Musculoskeletal injury expected to impact exercise in the protocol
• A positive pregnancy test at any point in the study
• Study physician discretion based on any other medical condition or medication
• Inability to understand or follow instructions or the protocol
• Gastrointestinal disease or previous surgery prohibiting core temperature capsule use. Participants with a contraindication can opt to insert the pill rectally as a suppository.

Aggregate results will be shared via publications and/or presentations. De-identified data may be shared and reviewed by the Department of Defense and as part of our Cooperative Research & Development Agreement with the United States Army Research Institute of Environmental Medicine.