Ambient Temperature and Thermoregulation During Exercise in Children and Youth

Inclusion Criteria: * Healthy male or female. * Aged 9-16 years or 20-25 years. * Habitually active, defined as participating in regular physical activity at least 3 times per week for at least 20 minutes per session over the previous 6 months. * Able to understand and communicate in English or French. * For participants younger than 18 years, written parental or guardian consent and participant assent are required. Exclusion Criteria: * Acute illness at the time of testing (e.g., cold, flu, or infection). * History of a chronic medical condition that may affect thermoregulation, cardiovascular function, or exercise capacity (e.g., cardiovascular disease, metabolic disorders, respiratory disease including asthma requiring regular medication, or neurological disorders). * Use of medications known to affect thermoregulation, hydration status, or cardiovascular responses. * History of heat-related illness (e.g., heat exhaustion or heat stroke). * Digestive abnormalities or gastrointestinal conditions that may contraindicate ingestion of a telemetry pill. * Any condition that, in the opinion of the investigators, would compromise participant safety or the integrity of the data.