From August 1, 2026, Texas UIL requires outdoor practice to be adjusted by WBGT: in Class 3 areas from 82.0°F (27.8°C) and in Class 2 areas from 79.7°F (26.5°C), rest breaks get longer and a cold-water immersion cooling zone is required; outdoor practice stops at 92.1°F and 89.8°F respectively.
Previously this chart was only a "recommendation." Starting with the 2026-2027 school year, it becomes a standard that all UIL member schools must follow for outdoor athletics and marching band activities.
UIL WBGT Chart (°F/°C)
First confirm whether your school is in Class 2 or Class 3 (explained in the next section), then compare with your on-site WBGT reading. The values in the chart are WBGT, not air temperature and not heat index.
| Class 3 (most of Texas) | Class 2 (a band in West Texas) | How to adjust practice |
|---|---|---|
| Below 82.0°F (27.8°C) | Below 79.7°F (26.5°C) | Normal practice; at least 3 rest breaks per hour, each at least 3 minutes |
| 82.0～86.9°F（27.8～30.5°C） | 79.7～84.6°F（26.5～29.2°C） | Use discretion for intense or prolonged exercise; at least 3 rest breaks per hour, each at least 4 minutes; a cold-water immersion cooling zone is required on site (ice tub or tarp) |
| 87.0～90.0°F（30.6～32.2°C） | 84.7～87.6°F（29.3～30.9°C） | Practice limited to 2 hours; football: helmet, shoulder pads and shorts only (if the reading rises into this category during practice, players may keep their pants on); all sports: at least 4 rest breaks per hour, each at least 4 minutes; cooling zone required |
| 90.1～92.0°F（32.3～33.3°C） | 87.7～89.7°F（30.9～32.1°C） | Practice limited to 1 hour; football: no protective equipment and no conditioning; all sports: a total of 20 minutes of rest spread through the hour; cooling zone required |
| 92.1°F (33.4°C) and above | 89.8°F (32.1°C) and above | No outdoor practice; wait until WBGT drops before resuming |
During rest breaks, students should be able to drink freely and do no activity at all; never restrict water at any time.
Is my school in Class 2 or Class 3?
UIL uses a U.S. WBGT regional map. On this map, most of Texas is Class 3; a band of West Texas running south from the Panhandle is Class 2. Class 2 thresholds are lower because students there are less used to high heat and humidity.
If your school is near the boundary between the two, the UIL FAQ says the school decides, ideally before the school year starts, and uses the same category for the whole season; it is recommended (but not required) to notify your District Executive Committee and the other schools in your district.
With the University of North Carolina (UNC) WBGT forecast tool, enter the practice site address and choose "Texas UIL Class 2" or "Texas UIL Class 3" as the flag category to see the matching category.
When to measure and how often
- Within 15 minutes before practice starts, you need a reading. If you use an on-site instrument, set it up and turn it on 30 minutes before practice so the reading can stabilize.
- Every 30 minutes during practice, take a reading. UIL says continuous monitoring is not required, and activities do not have to change mechanically every 30 minutes.
- Have the same person take all readings for a practice whenever possible, so the numbers are consistent.
- Practice time runs from when students arrive at the outdoor practice area until they leave.
- If WBGT rises into a stricter category during practice: switch to the stricter category's requirements. You do not have to stop immediately; coaches and athletic trainers decide based on how long practice has run, how much is left and how the students are doing. When WBGT drops you may relax the requirements, but do not automatically extend practice because of it.
- Covered pavilions and non-air-conditioned indoor facilities must be measured too; UIL recommends using a handheld instrument at the practice surface.
Rapid Cooling Zone Rules
Whenever outdoor athletics or marching band practices, games or conditioning take place at a WBGT of 82.0°F or higher in Class 3, or 79.7°F or higher in Class 2, a cold-water immersion cooling zone must be ready on site: an ice-water tub that can be used immediately, or a tarp filled with ice water and wrapped around the body (the TACO method). Ice sponges, towels, misting and shade are also encouraged, and it is recommended that a staff member or volunteer trained in cold-water immersion be present. Each school's Emergency Action Plan (EAP) must also include on-site cooling procedures.
Rules for Official Competition
No. The practice time and equipment limits in the chart do not apply to official UIL contests, but UIL recommends monitoring WBGT before and during games and considering a later start time, extra timeouts, a longer halftime, sideline shade and misting; in extreme weather, schools may reschedule. If WBGT reaches the threshold or higher during a game, a cooling zone is still required on site.
Handheld meters, online forecasts or a fixed monitoring station?
UIL accepts two approaches: a scientifically validated on-site WBGT instrument, or an approved online WBGT forecast tool. UIL's rules and FAQ do not name any brand or model. The three common approaches compare as follows:
| Handheld WBGT meter | Online WBGT forecast (e.g., the UNC tool) | Fixed WBGT monitoring station | |
|---|---|---|---|
| What it measures | Measures wherever you take it, including at the practice surface | An estimate based on an address, not a measurement of your own field | Set up beside the practice field, measuring conditions on site |
| What to do 30 minutes before practice | Take it out, turn it on and wait for the reading to stabilize | Check the website | Always on; nothing to prepare |
| A reading every 30 minutes | Someone has to remember to check and write it down | Someone has to remember to look it up | Numbers update continuously and can be viewed on phones and computers |
| Who knows when the category rises | Whoever reads it has to tell the coaches | Whoever looks it up has to tell the coaches | Can sound a light-and-siren alarm beside the field and send text, email or app alerts at the same time |
| Records | Usually written by hand or downloaded separately | You have to take screenshots or copy it down | Saved to the cloud automatically and easy to look back on |
| Suitable | Spot checks, comparisons, covered pavilions and indoor facilities | Scheduling practice times and preparing ahead | Schools that practice on the same field every day |
The three can be used together: check the forecast the day before to plan practice times, watch the fixed station during practice, and use a handheld meter for spot checks at other fields and to cross-check the station. UIL does not require records to be kept, but recommends that schools keep WBGT readings for outdoor practices; if a student has a problem, you can look back at the numbers from that time.
Heat Safety Guardian: set up beside the field, it measures and alerts on its own
Heat Safety Guardian is a fixed WBGT monitoring station developed in-house by YenProtek. Originally used on construction sites and for outdoor work, it also suits practice fields:
- Calculates WBGT on its own: measures air temperature, humidity, black globe temperature, wind speed and wind direction together and calculates WBGT in real time.
- Set your own thresholds: alert thresholds can be customized for your site, for example at the category boundaries in your area's UIL chart.
- Three-way alerts when a threshold is exceeded: the light-and-siren alarm at the field sounds while text, email or app push notifications go to athletic trainers and coaches, and the cloud keeps the data and event log from before and after the alert.
- No power or network cables to run: the standard kit includes a solar power module and an NB-IoT communication module.
- Multiple fields on one screen: football fields, practice fields and band practice fields can all be viewed on the same cloud dashboard.
For specifications and kit contents, see the Heat Safety Guardian product page; to find out how many units your fields need and how to set them up, go straight to an online quote.
Frequently Asked Questions
Q1: Are the UIL WBGT rules mandatory?
Yes. UIL first listed WBGT as a recommended practice in 2023. On June 10, 2026, the Legislative Council approved making it a required standard, effective August 1, 2026 for the 2026–2027 school year, for outdoor athletics and marching band activities at all UIL member schools. Violations are handled by the District Executive Committee and, if necessary, referred to the State Executive Committee.
Q2: Are the numbers in the UIL chart air temperature?
No. UIL specifically notes that the values in the chart are WBGT, not air temperature or heat index. WBGT takes air temperature, humidity, wind speed and sunlight into account together; on two 90°F days, WBGT is much higher when it is humid and sunny. For the difference between the two, see "Heat Index vs. WBGT: What's the Difference?"
Q3: Do we have to buy a WBGT meter? Can we use a phone app?
The UIL accepts approved online WBGT forecast tools as well as on-site instruments. A forecast is estimated from an address, not measured on your own field. WBGT can also differ between grass, artificial turf, track, and other surfaces. To know the actual number on the field, you still need to measure at the practice site.
Q4: If WBGT rises one category during practice, do we have to stop right away?
Not necessarily. UIL says to switch to the stricter category's requirements, with coaches and athletic trainers deciding based on how long practice has run, how much is left and how the students are doing. If it reaches the "no outdoor practice" category (92.1°F or higher in Class 3, 89.8°F or higher in Class 2), outdoor practice must stop.
Q5: How long should WBGT readings be kept?
UIL does not require readings to be kept and sets no retention period; it only recommends that schools keep a record of WBGT readings for outdoor practices. A fixed monitoring station saves the data to the cloud automatically, so there is nothing to write down by hand.
Q6: Do middle schools and bands have to follow it too?
UIL's rules state that they apply to outdoor athletics and marching band activities, and the cooling zone requirement includes marching band too. The UIL FAQ does not say separately whether middle school and sub-varsity teams follow it exactly; follow your school district's rules.
Q7: Does the UIL chart apply to construction sites and outdoor work?
No. The UIL chart is for school athletics. For workplaces, the U.S. currently has no federal heat standard: OSHA enforces under the General Duty Clause, and its National Emphasis Program on heat hazards, effective April 10, 2026, treats days with a forecast heat index of 80°F (26.7°C) or higher as heat priority days. OSHA's proposed heat injury and illness prevention standard from 2024 uses heat index triggers of 80°F and 90°F (26.7°C and 32.2°C) and also allows WBGT; as of mid-November 2026 it is still under review and not final. Heat Safety Guardian works on construction sites and industrial sites as well.
Q8: Can Heat Safety Guardian be used in the United States?
Send us the site address and we will check the local communication network and how we can supply it; overseas customers receive remote technical support. Alerts are sent by text message, email and app push notification.
References
- UIL, 2026-2027 Heat Stress & Athletic Participation REQUIRED Plan (WBGT chart, regional map, measurement timing, cooling zones)
- UIL, Heat Stress and Participation FAQs (boundary schools, rising categories during practice, records, games, violations)
- UIL，Legislative Council Meeting Results（2026-06-10）
- Occupational Safety and Health Administration (OSHA), CPL 03-00-024 National Emphasis Program on heat hazards (2026-04-10); proposed Heat Injury and Illness Prevention standard (89 FR 70698)
Last updated: November 14, 2026. UIL may update its rules each school year; always follow UIL's latest announcements.
For how WBGT is calculated, see "WBGT Formula"; for handheld meters vs. fixed monitoring stations, see "How to Choose a WBGT Meter".
