A big "well done" to the South Carolina High School League for requiring Wet Bulb Globe Thermometers (WBGT) at both high school and middle schools starting July 2018.
According to the National Weather Service, the Wet Bulb Globe Temperature is a reading from the thermometer that "takes into account temperature, humidity, wind speed, sun angle and cloud cover (solar radiation)."
The Heat Index ("how hot it feels") is another measurement that can be used to determine heat exposure limits and "takes into consideration temperature and humidity and is calculated for shady areas".
Both can be used to establish exposure limits for hot environments; however, the WBGT has two main advantages: it takes into account sun and wind exposure and it is taken at the location of the practice/competition. The Heat Index reading is taken at a weather station, so both the distance from the venue and the time of day of the reading make the heat index not quite as accurate an assessment of the heat risk.
If your sports organization has access to a WBGT that is great, but if it does not heat index is perfectly fine to use. The nice thing about the Heat Index is that all admins, coaches, and parents can download the OSHA Heat Safety Tool App for free. The most important thing is that your child's youth sports organization has a heat safety policy and that heat risk is being measured.
If your organization is going to use a WBGT, there are some questions that must be asked to determine if proper procedures are in place.
Which coach gets the WBGT?
What about the other coaches?
If only one WBGT is available per school, is the WBGT reading communicated to all the other coaches? When? Using what system (e.g. group text)?
Is each sport's practice at the same time and/or same location? If not, how does the coach get a reading if he/she does not have the WBGT?
Is the reading documented daily?
By what method is it documented?
Is this information available to the parents? In real time (daily, at the time the reading is made)? By request only?
Does everyone have the WBGT guidelines?
For Heat Index guidelines, see the Tennessee Secondary School Athletic Association Heat Policy.
In South Carolina, these are the Fall and Spring Sports:
Fall: Cheerleading, Cross Country, Football, Girl's Golf, Swimming, Girl's Tennis, Girl's Volleyball
Spring: Baseball, Boy's Golf, Soccer, Softball, Track
The SCHSL has a heat stress page. It states that each district has a heat policy. We looked at the Spartanburg School handbook and there is nothing mentioned other that that the coaches must take the NFHS Heat Illness course. We hope a complete heat policy is in place and that all coaches receive the WBGT measurement when they need it.
Here is a detailed heat resource: the CDC Occupational Exposure to Heat and Hot Environments