The information below is purely informational; several of you have asked about this new standard, so I figured I would try to explain it as best as I could. The explanation below is kind of wordy, but if you do wonder about this - here it is!
WHEN IS "HOT", "TOO HOT"?
Just as protocols for things like concussions have changed over the years, so, too has there been a focus on heat stress among athletes. About 20 years ago, Korey Stringer, a lineman for the Minnesota Vikings, died at a practice due to heat stroke. Unfortunately he is not alone; every year we hear of other athletes at all levels who tragically lose their lives. Organizations such as the NFHS (National Federation of High Schools) the NATA (National Athletic Trainers Association) and the Korey Stringer Institute, among others, have explored how best to create criteria to determine when "hot" is "too hot". The most effective measurement, they have found, is something called Wet Bulb Globe Temperature (WBGT) readings.
WBGT is measured by taking into effect such conditions as temperature, humidity, wind speed, and cloud cover. It is best measured by a device such as a Kestrel which is a hand-held or fixed device about the size of a cell phone that takes into account these various measurements. It produces a WBGT reading which is then compared to a chart which advises what should happen to athletic events for the day - should they be allowed, restricted, or cancelled. The United States is divided into zones, as well - South Florida and Texas has higher thresholds than New Hampshire, based solely on acclimatization to heat.
Last year the NFHS donated a number of Kestrel Heat Stress Trackers to State Associations such as the NHIAA. I was able to get one of these at no charge, and so on clearly hot and humid days you may see me in the middle of the fields taking measurements, and possibly setting restrictions on practices or games if necessary.
I understand that this is a whole new phenomenon - it is for me as well. Hopefully you understand that this is done to keep our kids safe, and I appreciate your understanding as we all get used to this new procedure.
If you wish to read or know more, I have included two links below. One is a WMUR story as they interview the head of the NHIAA regarding the heat, the other is from the Korey Stringer Institute - it is a more technical explanation including the charts that I use (we are Cat 1) to determine events for that day.
Last, and just as a further point of information, all of our coaches take and are certified in a Heat Illness Prevention course that is provided by the NFHS.