Overview
- The University Interscholastic League made WBGT monitoring mandatory for all member schools effective Saturday, August 1, requiring schools to use WBGT instead of the traditional heat index to decide whether outdoor practices can proceed.
- Under the new rules schools must take a WBGT reading before outdoor practices, repeat checks every 30 minutes, and follow clear activity limits that can shorten, delay, or cancel sessions when thresholds are exceeded.
- Schools must have rapid-cooling equipment and protocols on site, including the capacity for full-body cold-water immersion or equivalent measures, to treat athletes showing signs of heat illness immediately.
- Many districts spent the summer buying WBGT monitors and updating emergency plans, and coaches are already shifting practices to early morning or evening start times, shortening sessions, or moving workouts indoors to avoid high readings.
- WBGT combines wet-bulb, globe and dry-bulb measurements to account for humidity, solar radiation, wind and air temperature, a method developed in the 1950s for military training that experts now consider the most accurate way to judge outdoor heat stress for athletes and marching bands.