The UIL Heat Rule Has Been in Effect Since August 1 and May Reduce or Suspend Outdoor Practices When the WBGT Index Reaches Dangerous Levels
Schools affiliated with the University Interscholastic League (UIL) must now measure heat conditions before and during outdoor athletic practices and marching band rehearsals.
The new protocol took effect on August 1, 2026 for the 2026-2027 school year. Schools must obtain a reading within the 15 minutes preceding the start of the activity and repeat it every 30 minutes while the practice or drill continues.
The rule affects students participating in school sports, conditioning, and marching bands. It also covers practices conducted under covered pavilions or inside facilities that lack air conditioning.
The WBGT Heat Index Incorporates Humidity, Wind, and Sun Exposure
Schools will use the Wet Bulb Globe Temperature, known as WBGT. This measurement combines air temperature with humidity, wind speed, and solar radiation to calculate the stress heat can place on the body during physical activity.
Therefore, a WBGT reading is not equivalent to the temperature shown by a standard thermometer nor to the heat index that appears in weather forecasts.
That distinction is especially important in the Houston area. Humidity can raise thermal stress even when the air temperature is the same as in a drier part of Texas.
Schools can obtain the reading with an on-site instrument or through an approved digital forecast resource. When using a physical meter, UIL indicates that the equipment must be placed 30 minutes before practice.
The reading every 30 minutes does not require interrupting the session for minor changes. The responsible staff compare the conditions to the UIL table and adjust the practice when the measurement enters a more restrictive level.
Practices May Be Reduced to One Hour or Suspended
The thresholds of the Class 3 category, corresponding to warm and humid areas like Houston, establish these conditions for practices:
- Less than 82.0 WBGT: the activity may continue with at least three breaks per hour, each lasting three minutes.
- From 82.0 to 86.9: schools must monitor vigorous or prolonged exertion and provide at least three four-minute breaks per hour.
- From 87.0 to 90.0: outdoor practice may not exceed two hours. All sports and bands require at least four four-minute breaks per hour. In football, players are limited to helmets, shoulder pads, and shorts.
- From 90.1 to 92.0: practice is limited to one hour, including 20 minutes of rest. No protective equipment or additional conditioning exercises are allowed.
- 92.1 or higher: outdoor practices or training are not permitted until the WBGT drops.
The rest periods allow water drinking without restrictions and cannot be used for exercises, physical instruction, or other activities.
If conditions worsen during a session, the school staff should switch to the corresponding restrictions. UIL allows consideration of how long the practice has lasted, the trend of readings, the condition of participants, and recovery opportunities.
Schools Need Equipment to Cool the Body Quickly
Schools must also have a rapid cooling area when activities occur with a WBGT reading of 82.0 or higher under the Houston classification.
That area requires equipment capable of immersing the body in ice-cold water. A tub or a tarp that can be filled with ice and water can serve this function. Shade, fans, misters, and cold towels can complement the area but do not replace the immersion system.
Additionally, each school’s emergency plan must include procedures to recognize a heat-related illness, initiate cooling, and summon emergency medical services.
Duration Limits Do Not Apply the Same Way to Games
The restrictions on duration, equipment, and conditioning apply to practices and workouts. They do not automatically apply to games, performances, or official competitions.
However, schools must maintain a rapid cooling zone during a competition when the WBGT reaches 82.0 or higher in Class 3. UIL also contemplates schedule changes, additional water breaks, access to air-conditioned spaces, shade, fans, and longer breaks.
Campuses may modify or reschedule a competition when extreme heat conditions prevent safe participation.
The full table, application questions, and resources for consulting WBGT are available in UIL’s mandatory heat protocol for 2026-2027.
The new rule will remain in effect throughout the 2026-2027 school year for UIL-covered athletic and marching band activities.
