On this page · 8 sections
What does CHSAA ask of schools?
The CHSAA Sports Medicine Advisory Handbook is a collection of best practices. It says itself that it is not intended to be construed as policy, but CHSAA and its Sports Medicine Advisory Committee point coaches to its WBGT chart to decide practice modifications. Colorado is a Category 1 state, so the chart uses the lowest, most protective set of WBGT bands.
Schools can read WBGT from a monitoring device or from the National Weather Service WBGT tool, zoomed to the practice site. The handbook pairs the chart with prevention steps: a venue-specific emergency action plan practiced every season, warm-ups and breaks in the shade, scheduled rest and hydration in the heat, gradual acclimatization, and the means to cool an athlete rapidly.
Category 1
Colorado is a Category 1 state, so normal activity stops at 76.1 and outdoor workouts stop at 86.2.
Reading the WBGT
A WBGT monitoring device at the site, or the National Weather Service WBGT tool clicked on your practice location.
Cooling
Cool first, transport second. A cold tub is best; cold towels, ice and fans if a tub is not available.
Air quality
CHSAA's heat reminder pairs WBGT with AQI: modify or move practice indoors above 100, consider postponing above 200.
The CHSAA WBGT activity table
Five bands, read in degrees Fahrenheit, for Colorado as a Category 1 state. The row colour follows the Flash alert scale your athletic trainers already see in the app.
| WBGT (°F) | Activity limit | Rest breaks | Football equipment |
|---|---|---|---|
| < 76.1 | Normal activities | At least three separate rest breaks each hour with a minimum duration of 3 min each | None listed |
| 76.3 – 81.0 | Use discretion for intense or prolonged exercise | At least three separate rest breaks each hour with a minimum duration of 4 min each | None listed |
| 81.1 – 84.0 | Maximum practice time is 2 h | At least four separate rest breaks each hour with a minimum duration of 4 min each | Helmet, shoulder pads, and shorts during practice |
| 84.2 – 86.0 | Maximum practice time is 1 h | 20 min of rest breaks distributed throughout the hour of practice | No protective equipment; no conditioning activities |
| ≥ 86.2 | No outdoor workouts. Delay practice until a cooler WBGT is reached | — | — |
Source: CHSAA Sports Medicine Advisory Handbook, Heat Illness, Monitoring Environment and WBGT Monitoring (updated 3/6/2024, chsaanow.com), checked 15 Oct 2026. Ranges as printed. If the WBGT rises into 81.1–84.0 during practice, football players may continue to work out wearing football pants without changing to shorts. The handbook is best-practice guidance, not policy; check your league and district rules too.
Where does Flash fit?
Flash is a forecast for planning, not an on-site meter: decide modifications from the WBGT at your practice site. Flash's 6-hour WBGT outlook tells you at 1 pm what the 4 pm reading is likely to be, so you can move practice instead of cancelling it.
Heat: plan, don't cancel
The outlook runs per field for every hour of the afternoon, against the five Category 1 bands. Shift the start, swap the equipment plan or go indoors before the cars arrive.
Lightning: up to 60 minutes ahead
Strike-level prediction on a 1×1 km cell, refreshed every 2 minutes. Up to 99.6% lightning prediction accuracy on a one-hour window, measured against NLDN ground-truth strikes — method published.
Accuracy methodReturn to play: the all-clear timer
After the last strike inside your radius, Flash runs your policy's all-clear timer and logs it, so play resumes on evidence.
Weather Command Center
Flash Heat and WBGT prediction 6-hour WBGT outlook, heat index, air temperature and dew point per 1×1 km cell
What does a planning day look like?
Illustrative example · Not live weather — the readings are examples, the bands are CHSAA's (Category 1)
6:30 pm · The reading that decides the day
The band you land in sets the clock, the breaks and the pads.
Flash 6-hour WBGT outlook for the practice field: 84 by 3 pm, into 84.2–86.0 by 4 pm. The athletic director flags the football session.
Decision: run at 4 pm under a 1-hour cap with no pads, or push to 6:30 pm. The AD pushes. The bus, the trainers and the parents hear now, not at 3:45.
WBGT at the field: 82.9, the 81.1–84.0 band. A 2-hour practice in helmets, shoulder pads and shorts, with four 4-minute breaks each hour.
Flash lightning alert: a strike is predicted inside the site radius within the next 60 minutes. The field clears.
Last strike inside the radius. Flash starts the all-clear timer.
All clear. Practice resumes; the alert log records who was warned, when, and when play returned.
What should the athletic director keep on file?
CHSAA's handbook is guidance, so the record is yours to set. Keeping these together means a question from CHSAA, the district or a parent is answered from one folder.
- WBGT readings with times and where they came from: an on-site device or the National Weather Service WBGT tool.
- The band each reading fell in and the decision it triggered: practice length, rest breaks, football equipment.
- The venue-specific emergency action plan, practiced at the start of every season, with the cold tub or cooling setup.
- AQI checks on smoky days, and any practice moved indoors or postponed because of them.
- The Flash alert log: lightning alerts, who was notified, the all-clear, and the 6-hour outlook the schedule decision was based on.
Which other states publish WBGT policies?
Every state page follows this template: verified thresholds, the reading cadence, what to keep on file, and where the WBGT forecast fits.
State by state
Same instrument, different bands — the WBGT forecast travels with you.
- Georgia (GHSA)
- Texas (UIL)
- Florida (FHSAA)
- Arizona (AIA)
- Arkansas (AAA)
- Hawaii (HHSAA)
- Illinois (IHSA)
- Kansas (KSHSAA)
- Massachusetts (MIAA)
- Mississippi (MHSAA)
- Missouri (MSHSAA)
- Nevada (NIAA)
- New Hampshire (NHIAA)
- New Mexico (NMAA)
- North Carolina (NCHSAA)
- Ohio (OHSAA)
- West Virginia (WVSSAC)
- Oklahoma (OSSAA)
- Alabama (AHSAA)
- California (CIF)
- Connecticut (CIAC)
- Iowa (IHSAA / IGHSAU)
- Kentucky (KHSAA)
- Louisiana (LHSAA)
- Minnesota (MSHSL)
- Nebraska (NSAA)
- New Jersey (NJSIAA)
- New York (NYSPHSAA)
- South Carolina (SCHSL)
- South Dakota (SDHSAA)
- Utah (UHSAA)
- Vermont (VPA)
- Virginia (VHSL)
- Washington (WIAA)
- Wisconsin (WIAA)
Sources
- CHSAA — Sports Medicine Advisory Handbook, Heat Illness and WBGT Monitoring, Category 1 WBGT activity chart (updated 3/6/2024). Checked 15 Oct 2026.chsaanow.com/documents/2026/3/25/SMAC_HANDBOOK_57_.pdf (opens in a new tab)
- CHSAA — SMAC Alert: Heat Illness and Air Quality Reminders, 6 Aug 2025. WBGT tool, the Colorado WBGT chart, AQI and hydration. Checked 15 Oct 2026.chsaanow.com/news/2025/8/6/general-smac-alert-heat-illness-and-air-quality-reminders.aspx (opens in a new tab)
CHSAA documents are published at chsaanow.com (opens in a new tab).
Frequently asked
No. The CHSAA Sports Medicine Advisory Handbook is a collection of best practices and says it is not intended to be construed as policy. CHSAA still directs coaches to the chart to decide practice modifications, and districts or leagues may adopt it.
Colorado is a Category 1 state, and the regional WBGT categories set lower limits for cooler climates. The Category 1 bands start restricting practice at lower readings: outdoor workouts stop at 86.2.
No. Decide modifications from the WBGT at your practice site. Flash's 6-hour outlook tells you where that reading is heading — a scheduling tool, not a measuring instrument.