Efficacy of Electric Fans in Children During Heat Waves

Extreme heat exposure is an escalating global public health concern, with climate change driving increases in the frequency, duration, and intensity of heat events. Projections indicate substantial increases in heat-related morbidity and mortality in the coming decades, including among children and youth, who are increasingly recognized as a physiologically vulnerable population. The purpose of this project is to evaluate the effectiveness of commonly used heat-mitigation strategies, specifically midday access daylong electric fan use, in reducing physiological strain and maintaining cognitive function, perceptual comfort, and psychological well-being in children and youth exposed to prolonged indoor heat. The study also aims to determine whether these strategies provide comparable protection in children and youth relative to young adults. Participants will complete four sessions under the same environmental conditions (31°C and 36°C), with each temperature completed twice: once with continuous electric fan use and once without fan use. The four sessions therefore consist of: (1) 31°C without fan use; (2) 31°C with fan use; (3) 36°C without fan use; and (4) 36°C with fan use.

Inclusion Criteria: * Participants must be healthy males or females within the specified age ranges (9-12 years, 13-16 years, or 20-25 years). * All participants must be habitually active, defined as participation in regular physical activity at least three times per week for a minimum of 20 minutes per session over the previous six months. * Participants must be able to understand and communicate in English or French. * For participants under 18 years of age, written parental or guardian consent and participant assent will be required prior to participation. Exclusion Criteria: * Individuals will be excluded from participation if they have any acute illness at the time of testing (e.g., cold, flu, or infection), or a history of chronic medical conditions that may affect thermoregulation, cardiovascular function, or exercise capacity, including but not limited to cardiovascular, metabolic, respiratory, or neurological disorders. Individuals taking medications known to influence thermoregulation, hydration status, or cardiovascular responses will also be excluded. * Participants with a history of heat-related illness (e.g., heat exhaustion or heat stroke) will not be eligible. * Individuals with digestive abnormalities or gastrointestinal conditions that may contraindicate ingestion of a telemetry pill will also be excluded. * Any individual who, in the opinion of the investigators, may be at increased risk or unable to safely complete the study procedures will be excluded.