Coaches’ Resources

Outdoor practice limits use WBGT. Confirm the estimate with an on-site reading or approved app before practice.

• MHSAA: these regulations “DO NOT remove the need to have a cold tub available for all outdoor practices.” Some athletes overheat earlier because of size, fitness, or health.
• Free WBGT apps named by MHSAA: WeatherBug, Google Weather (Android), Carrot Weather, and Weather FX.

This page estimates WBGT with the Liljegren model using forecast temperature, humidity, wind, air pressure, and sunlight. Field conditions can differ. The estimate is not a measurement.

Source: MHSAA WBGT guidance.

• Remove unnecessary clothing and equipment, submerge the athlete up to the chest in an ice bath, and circulate the water around the body for at least 20 minutes.
• If the athlete is confused, combative, or shows any change in mental status: call EMS and begin cooling immediately. Keep the athlete in cold water for at least 20 minutes before transport to the hospital, longer if possible.

Source: MHSAA SMAC Heat Update 2026.

• These lightning guidelines cover both games and practices. A lightning detector is required at outdoor events and should be on and monitored at practices when severe weather is possible. It supports, and does not replace, common sense and what you can see.
• 40 miles: monitor the detector closely once lightning is detected within 40 miles.
• 15 miles: the host game administrator notifies the officials. The game administrator, the principal (if available), and the officials decide together whether to postpone, using the detector, visual warnings, and radar.
• 10 miles: the activity is postponed and evacuation plans take effect. At practice, the head coach moves athletes and staff inside to a safe facility at 10 miles.
• Resume using the same criteria. Officials may use the existing 30/30 policy.
• Each school has an emergency plan for moving athletes and spectators to safe shelter in a reasonable time.
• Anyone may leave an athletic site to seek safe shelter, without fear of penalty, if they believe they are in danger from lightning.

This page has no lightning-distance data. For live strikes, use your lightning detector or a strike map such as LightningMaps.org or Blitzortung.org (community networks, not official).

Source: MHSAA lightning guidelines. NWS alerts and forecast thunderstorms do not establish a lightning distance or permission to resume.

1. Good (0–50)

   Great day to be active outside!

2. Moderate (51–100)

   Good day to be active outside! Students who are unusually sensitive to air pollution could have symptoms.

3. Unhealthy for Sensitive Groups (101–150)

   It’s OK to be active outside, especially for short activities such as recess and PE. For longer activities such as athletic practice, take more breaks and do less intense activities. Watch for symptoms. Students with asthma should follow their asthma action plans and keep their quick-relief medicine handy.

4. Unhealthy (151–200)

   For all outdoor activities, take more breaks and do less intense activities. Consider moving longer or more intense activities indoors or rescheduling them. Watch for symptoms. Students with asthma should follow their asthma action plans and keep their quick-relief medicine handy.

5. Very Unhealthy (201–300)

   Move all activities indoors or reschedule them to another day.

6. Hazardous (301+)

   Not listed in the EPA school guide. Air is worse than Very Unhealthy, so at minimum move all activities indoors or reschedule.

Plan ahead for ozone: there is less ozone in the morning, so on high-ozone days plan outdoor activities in the morning. Source: EPA, Air Quality and Outdoor Activity Guidance for Schools (EPA-456/F-14-003, 2014; AQI ranges from the standard AQI categories).