Predicting Responses to Exhausting, Prolonged, And Repeated Exercise Demands (PREPARED) for Heat

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.