How new UIL heat rules reshaped high school football practice in San Antonio

It’s 4:45 in the morning, and New Braunfels Long Creek head coach Adam Harvey hops into his truck to head to practice. But before he even turns on any music, Harvey grabs his phone and opens the Perry Weather app to check the WBGT reading, something the UIL began requiring its member schools to utilize this year.

As of Aug. 1, the use of wet-bulb globe temperature (WBGT) readings became mandatory for all UIL athletic programs and marching bands during any outdoor practice. The UIL first started recommending schools use WBGT readings in 2024 to determine if outdoor conditions were safe enough to practice in as a response to record-breaking heat across the state.

Escaping the heat

This is the first story in a multi-part series on the UIL’s new mandatory requirement of wet bulb globe temperature (WBGT) measurements as part of an effort to combat heat across the state.

What wet bulb globe temperature (WBGT) is and why the UIL now requires its members to utilize it for outdoor practices.

How have coaches adjusted practices and even junior high schedules to abide by WBGT guidelines.

How a few districts are going beyond just following the guidelines to protect their students from the heat.

2024 was the same year San Antonio recorded its hottest year on record, with 2023 and 2025 tying for the second hottest year in the city’s history.

“I think it’s imperative that we take precautionary measures to really take care of these kids,” Harvey said.

Unlike the standard dry-bulb temperature, which is what is usually shown on weather apps and local TV, the wet-bulb globe temperature accounts for temperature, humidity, sky cover and wind speed, according to Express-News meteorologist Anthony Franze.

External factors outside of the temperature itself, like humidity, can be critical to determining the safety of outdoor conditions.

“Sweat evaporates off our skin and causes us to cool down,” Franze said. “However, when there’s too much moisture in the atmosphere, when it’s too humid, the sweat doesn’t evaporate as well and so our body doesn’t cool down as well, which causes the internal temperature to rise, forcing heat exhaustion, heat stroke to be more prevalent.”

The San Antonio area coaches and band directors that spoke to the Express-News about the new wet bulb rule said they agreed with the intention behind the new regulation.

“Player safety is of the utmost concern for all of us and so I definitely understand why the rule is in place,” East Central head coach Joe Hubbard said. “There’s been so many heat-related illnesses and deaths just over the years.”

Austin Bowie senior Justice Trumpler suffered a heat stroke during his 2023 season opener that landed him in the ICU. While Trumpler fully recovered days later, others aren’t as lucky. Guthrie football player Rue McNeil died in August 2020 after suffering from a heat stroke at practice.

“Incidents have happened, deaths have happened, so we’ve got to make sure that as coaches we don’t just see it as a negative and we kind of see it as a positive as well,” Lanier head coach Sal Tellez said. ” We’re taking care of somebody else’s child when they’re in our hands.”

Since many schools across Texas, including those in the three largest school districts in San Antonio (Northside ISD, North East ISD and San Antonio ISD), have been using WBGT measurements since the UIL initially made the recommendation in 2024, the UIL formally opted to make WBGT a requirement beginning this school year.

“So many were actually following the recommended policy, and so in some weird way it was punishing the ones that were doing everything we’re supposed to, but there were a few that were not,” UIL director of athletics Ray Zepeda said at the annual Texas High School Coaches Association (THSCA) convention in Houston on July 18.

The UIL has not defined an explicit punishment for schools that do not abide by WBGT guidelines, but those have not been a major concern.

“Texas coaches care about their kids and they follow rules,” Zepeda said in July.

Area coaches echoed a similar message.

“I’ve been in the profession now for about 25 years and I think most coaches would say they feel they do a really good job, along with their training staff, of taking good care of kids,” Hubbard said.

THSCA executive director Joe Martin said during the Sept. 13 UIL Medical Advisory Committee meeting that the “vast majority” of schools are following WBGT guidelines.

The UIL recommends WBGT readings to be taken 15 minutes before the start of outdoor practice and every 30 minutes once practice has started, and guidelines regulating outdoor practices become more restrictive as WBGT readings increase. Guidelines are also impacted by practice location. San Antonio, like most of Texas, is located in the area denoted as Class 3, which has the highest allowed WBGT readings for each level of requirements.

San Antonio area schools must adhere to these WGBT guidelines:

• Outdoor practices held in the Greater San Antonio area with WBGT measurements that fall between 82.0 and 86.9 require a mandatory rapid cooling zone, like a cold water immersion tub or tarps that can be filled with ice water to quickly lower somebody’s internal body temperature.

• For readings between 87.0 and 90.0, football players may wear helmets, shoulder pads and shorts in practice. If the WBGT reading reaches this threshold during a practice, football players can continue wearing football pants without needing to change into shorts. All outdoor practices at this level must have four rest breaks of at least four minutes every hour.

• Only one hour of outdoor practice is allowed when the WBGT readings range from 90.1 to 92.0. For football practices, players may not wear protective equipment and no conditioning is allowed. Twenty minutes of rest must be distributed within the hour for all outdoor sports and marching band. Outdoor practice is prohibited when WBGT readings reach 92.1 or higher.

Davenport band director Michael Lehmann said while he’s seen WBGT readings on his phone reach the level w.here outdoor practice is not allowed, it’s never happened during a scheduled rehearsal.

“We haven’t really had to stop a practice yet and come inside,” Lehmann added.

While the temperatures are starting to drop in San Antonio as we enter the fall season, coaches had to find new ways to adequately practice in the summer heat while abiding by WBGT guidelines, something that will be explored in the next part of this series.

“We tell our kids all the time, ‘Control what you can control,’” Harvey said. “We can’t control the new UIL policy of no practice when the wet bulb globe temperature is X, Y, Z, A, B, C. So therefore, we’re going to find solutions.”

Although the addition of a new rule has required various levels of adjustment by coaches, there remains a shared understanding of why the requirement of WBGT readings exists – to keep students safe.

“If we don’t like it because it’s a hard rule, it’s a difficult rule, or something that we’ve never done before, then we’ve got to find solutions that work within the means of it,” Harvey said. “Because it’s in place for a reason.”

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This article originally published at How new UIL heat rules reshaped high school football practice in San Antonio.