San Antonio- Beginning this fall, Texas schools must regularly measure heat conditions and modify—or cancel—outdoor practices when temperatures become dangerous.
Texas high school athletes, coaches and marching band members are beginning the new school year under stricter statewide heat-safety requirements.
Effective August 1, 2026, the University Interscholastic League requires every member school to follow its Heat Stress and Athletic Participation Guidelines. The standards had been recommended for the previous three years but are now mandatory.
The rules require schools to use Wet Bulb Globe Temperature readings, commonly known as WBGT, to determine whether conditions are safe for outdoor practices, workouts and marching band rehearsals.
Unlike the temperature displayed on a weather app, WBGT accounts for several factors that affect the body’s ability to cool itself, including air temperature, humidity, direct sunlight and wind.
San Antonio-area schools, where high humidity can make an already hot afternoon feel more dangerous, the readings could result in longer water breaks, reduced equipment, shorter practices or the cancellation of outdoor activities.
Readings Required Throughout Practice
Schools must take a WBGT reading within 15 minutes before an outdoor practice begins and continue taking readings every 30 minutes during the activity.
The requirement also covers practices held beneath covered pavilions and inside facilities that are not climate-controlled. Schools may use an approved on-site measuring device or an approved internet-based WBGT forecasting service.
The UIL divides Texas into different heat classifications based on regional climate. San Antonio and most of the state fall within Class 3, which uses the following practice restrictions:
When the WBGT is between 82.0 and 86.9 degrees, schools must provide a rapid cooling zone capable of treating a participant experiencing heat illness.
At readings between 87.0 and 90.0, football players are limited to helmets, shoulder pads and shorts. Outdoor programs must provide at least four rest breaks of four minutes each during every hour of activity.
When the WBGT reaches 90.1 to 92.0, outdoor practice is limited to one hour. Football players cannot wear protective equipment, conditioning drills are prohibited and at least 20 minutes of rest must be distributed throughout the session.
At a reading of 92.1 or higher, outdoor practices cannot be held.
Cooling Equipment Must Be Ready
Rapid cooling zones are required when the WBGT reaches 82 degrees in Class 3 areas such as San Antonio.
Those zones must include equipment capable of full-body cold-water immersion. Schools may use cold-water tubs or specially designed tarps filled with ice water.
Shade, fans, wet towels, water misters and ice sponges may supplement the cooling area, but they do not replace the full-body immersion requirement.
School emergency plans must also include procedures for recognizing heat illness, contacting emergency medical services and rapidly cooling an athlete or participant.
Games Treated Differently
The mandatory practice limits do not formally apply to games or other UIL contests.
Schools are still expected to monitor heat conditions during competitions and maintain rapid cooling equipment when required. Officials may also consider moving start times, adding hydration breaks, extending halftime, providing shaded sidelines or allowing athletes to wait in air-conditioned areas.
For sub-varsity events, schools may mutually agree to shorten quarters or make other adjustments when conditions become dangerous.
Football Players Continue Acclimatization Period
The heat standards work alongside existing football acclimatization rules.
During the first two days of fall practice, athletes may wear only T-shirts, shorts and helmets, and contact drills are prohibited. Shoulder pads and girdles may be added during days three and four, while full equipment and full-contact practice are not permitted until after the five-day acclimatization period.
Players who join the team after the opening day must complete their own five-day acclimatization period.
Violations Could Lead to UIL Review
Potential violations will be handled like other UIL rule infractions. Complaints may first be considered by the local District Executive Committee and could later be referred to the State Executive Committee.
Possible penalties could apply to individual coaches, athletic programs or schools.
UIL officials said the move to mandatory standards is intended to create consistency across Texas, not to suggest that schools have ignored athlete safety in the past.
For North San Antonio families, the most noticeable changes may include earlier practice times, additional water breaks, players wearing less equipment and occasional practices being moved indoors or canceled.
The UIL’s message is straightforward: when dangerous heat arrives, the practice schedule must change—not the safety standard.