On this page · 8 sections
What does the NHIAA require?
Section 12 of By-Law Article III asks schools to follow a statewide policy for practices and voluntary conditioning workouts in every sport, year-round, summer included. It covers three things: when practice can be scheduled at a given heat and humidity level, how much of each hour goes to rest and hydration, and the level at which practice stops. The NHIAA credits the policy to the Georgia High School Association, but the New Hampshire bands sit about six degrees lower.
A scientifically approved WBGT instrument should be used at each practice before October 1. Readings are taken at least every 30 minutes, starting 30 minutes before practice begins, and every WBGT monitor is calibrated at least every two years, or sooner if the manufacturer says so. During games, athletic directors, game officials and medical staff decide on modifications; in the postseason that authority sits with the NHIAA.
Reading cadence
First reading 30 minutes before practice, then at least every 30 minutes. An approved WBGT instrument at each practice before October 1.
The device
A scientifically approved WBGT monitor, calibrated at least every two years or sooner if the manufacturer recommends it.
Year-round, every sport
The policy covers practices and voluntary conditioning workouts in all sports, including during the summer.
Games and the postseason
Athletic directors, officials and medical staff can add rest breaks, delay or postpone. Postseason calls belong to the NHIAA.
The NHIAA WBGT threshold table
Five bands, read in degrees Fahrenheit from the on-site WBGT instrument: one table for the whole 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 |
|---|---|---|---|
| Under 76.1 | Normal Activities | Provide at least three separate rest breaks each hour with a minimum duration of 3 minutes each during the workout | None listed |
| 76.2 – 81.1 | Use discretion for intense or prolonged exercise; watch at-risk players carefully | Provide at least three separate rest breaks each hour with a minimum duration of 4 minutes each | None listed |
| 81.2 – 84.1 | Maximum practice time is 2 hours | For All Sports: Provide at least four separate rest breaks each hour with a minimum duration of 4 minutes each | For Football: players are restricted to helmet, shoulder pads, and shorts during practice, and all protective equipment must be removed during conditioning activities |
| 84.2 – 86.0 | Maximum practice time is 1 hour | For All Sports: There must be 20 minutes of rest breaks distributed throughout the hour of practice | For Football: no protective equipment may be worn during practice, and there may be no conditioning activities |
| Over 86.1 | No outdoor workouts. Delay practice until a cooler WBGT level is reached | — | — |
Source: NHIAA Handbook 2026-27, By-Law Article III, Sports Medicine, Sect. 12, WBGT Activity Guidelines and Rest Break Guidelines (pp. 61–62, nhiaa.org), verified 15 Oct 2026. Ranges as printed. If the WBGT rises into 81.2–84.1 during practice, football players may continue to work out in football pants without changing to shorts.
Where does Flash fit?
Flash is a forecast for planning, not an on-site meter: NHIAA guidance runs on the reading from your WBGT instrument. 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 NHIAA 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 rules are the NHIAA's
6:00 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: 80 by 3 pm, into 81.2–84.1 by 4 pm. The athletic director flags the football session.
Decision: run at 4 pm under the 2-hour cap with four 4-minute breaks an hour, or push to 6:30 pm. The AD pushes. The bus, the trainers and the parents hear now, not at 3:45.
First on-site WBGT reading, 30 minutes before practice: 79.4, the 76.2–81.1 band. Three 4-minute breaks per hour go on the plan; the next reading is due by 6:30.
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?
Section 12 does not set a records rule. Keeping these together still means a question from the NHIAA, the district or a parent is answered from one folder.
- WBGT readings with times: the first 30 minutes before practice, then at least every 30 minutes.
- The band each reading fell in and the decision it triggered: practice length, rest breaks, football equipment.
- The WBGT monitor used and its calibration date (at least every two years).
- The emergency action plan for heat-related illness.
- 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)
- Colorado (CHSAA)
- Hawaii (HHSAA)
- Illinois (IHSA)
- Kansas (KSHSAA)
- Massachusetts (MIAA)
- Mississippi (MHSAA)
- Missouri (MSHSAA)
- Nevada (NIAA)
- 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
- NHIAA — Handbook 2026-27, By-Law Article III, Sports Medicine, Sect. 12, Pre-Season Acclimatization and WBGT Guidelines (CM 11.25), pp. 61–62. Thresholds, reading cadence, calibration, competition authority. Verified 15 Oct 2026.assets-rst7.rschooltoday.com/rst7files/uploads/sites/586/2026/09/21142308/5HB-26-27-III-Sports-Medicine.pdf (opens in a new tab)
- NHIAA — Handbook index, nhiaa.org, linking the 2026-27 by-law articles. Verified 15 Oct 2026.nhiaa.org/about-nhiaa/handbook/ (opens in a new tab)
NHIAA documents are published at nhiaa.org (opens in a new tab).
Frequently asked
No. NHIAA guidance runs on the reading from a scientifically approved WBGT instrument at the practice site. Flash's 6-hour outlook tells you where that reading is heading — a scheduling tool, not a compliance instrument.
At least every 30 minutes, beginning 30 minutes before the start of practice. The NHIAA calls for the instrument at each practice before October 1.
The NHIAA adapted the Georgia policy but printed its own bands for New Hampshire. The 2-hour cap starts at 81.2 rather than 87.0, and outdoor workouts stop over 86.1.
Yes. The NHIAA statewide policy covers practices and voluntary conditioning workouts in all sports, year-round, including during the summer.