The Sports Medicine Australia extreme heat risk and response guidelines and web tool

The new extreme heat policy (EHP) issued by Sports Medicine Australia (SMA) in 2021 (SMA EHP v1 (2021)) was designed to protect healthy adults playing recreational sports from heat-related illness. Using a fundamental biophysical heat balance model to estimate heat stress risk, this extreme heat policy offered significant improvements on the policy previously used by SMA (2009). Yet, community feedback highlighted opportunities for further improvement. Specifically, heat stress risk was reportedly underestimated in very hot and dry extremes but overestimated in humid extremes. Due to SMA EHP v1 (2021) being a printed policy document, users were required to manually consult graphs for 40 sports - which were broadly classified into 5 separate groups - to determine the overall heat stress risk using temperature and humidity data extracted from local weather services - a process vulnerable to human error. Here, we propose a further updated SMA extreme heat policy (SMA EHP v2 (2024)). Adapting the validated International Standards Organisation Predicted Heat Strain model, updated heat stress risk curves were developed for the 40 most popular Australian sports with the aim of providing greater protection in very hot and dry extremes by accounting for high required sweat rates and additional cardiovascular strain. SMA EHP v2 (2024) reduces previously high rates of disruption to play in humid extremes by preferentially recommending active cooling and rest breaks. It also incorporates sport-specific metabolic rates, clothing and self-generated wind speeds to provide more precise estimations of heat stress risk. A freely accessible cross-platform web tool is described enabling convenient implementation with location specific, hour-by-hour risk classification, hierarchical recommendations of risk reduction strategies, and 7-day risk forecasting (https://sma-heat-policy.sydney.edu.au). Intended users are sporting administrators, coaches, and sport medical teams responsible for the safety and well-being of healthy adults engaging in recreational and community sports in hot weather, and people wishing to manage heat stress risk during planned training activities.