HeatTracking: monitoring heat-related symptoms in the community through participatory self-reporting

Mild and moderate severity health impacts of hot weather remain largely unmonitored. We piloted a participatory surveillance system for monitoring heat-related health impacts. FluTracking Australia volunteers in Sydney and Melbourne were invited to enrol in HeatTracking. For those who agreed to participate, a weekly survey collecting self-reported heat-related symptoms was sent for 9 weeks of the 2024/2025 Australian summer. Almost 20% of the invitees enrolled, resulting in 1,735 participants (61% female, 48% aged >64 years). Retention and adherence to survey completion were high. Heat-related health impacts were reported by 11.7%-21.0% of participants each week, and 0.7-3.0% of people with heat-related symptoms sought medical care. Factors associated with heat-related health impacts included older age, female sex, high apparent temperature, living in rental accommodation, high number of hours feeling too hot due to physical activity, and having a recent history of heat-related health impacts. Overall participant satisfaction was high with 93.1% of 610 who provided feedback indicating they would participate again. Future HeatTracking iterations should seek to minimise recall bias while capturing more precise timing and location of exposure, as well as a broader range of symptoms, preventive behaviours, and productivity impacts. A participatory surveillance approach to monitoring heat-related health impacts appears feasible.