by Renny Vandewege, special to SportsMD
While lightning, wind, tornadoes, and other extreme storm factors are always a top concern during athletic events, mitigating the risk and potential threats of them has improved significantly in the past ten years. In addition to these extreme weather events, there’s one other factor that needs continued attention and that is extreme heat. It is the number one weather cause of fatalities in the U.S. with 600 deaths on average annually, some of which are athletes suffering from heat stroke or exhaustion. There is a 100% survival rate when quickly recognized and treated so understanding and recognizing heat stress is a key factor in preventing injury.
Excessive heat pushes the human body beyond its limits, and when combined with exertion during athletics, it becomes dangerous. The danger comes specifically when extreme heat combines with high humidity, as the body’s natural cooling mechanism does not function as efficiently. When evaporation is slowed down and the body has to work harder to maintain a normal temperature, that’s when athlete’s succumb to heat-related illnesses.
Dangerous heat is most commonly measured by the heat index, but is more accurately measured by a wet bulb globe temperature (WBGT). The heat index is calculated using the outside air temperature and relative humidity. These readings are generally taken in the shade, which means that they may not reflect the actual setting on a field where athletes are playing. The heat index is the metric used by the National Weather Service to issue alerts and warnings.
The WBGT is a more comprehensive tool because in addition to the heat and humidity readings, wind speed and solar radiation are also used as measurements. This level of specific data is more beneficial to coaches and athletic trainers than the standard heat index.
Having the right heat stress information allows team leaders to make informed decisions about activity and hydration breaks during activity. For example, a WBGT under 82 F means that normal activities and practices, including three separate rest breaks each hour for a minimum of three minutes each, can be observed. However, once the WBGT gets above 82 F more caution needs to be exercised such as longer and more frequent breaks during heavy physical exercise. Once WBGT temperatures get above 90 F a significant amount of the body heat cannot escape and typically exercise or other physical activity should be stopped. These types of protocol will be important this upcoming summer as there’s high confidence that this summer will see average to hotter-than-normal temperatures across most of the country, particularly from the Plains westward.
Tools for measuring WBGT are specific and most free forecasts do not include WBGT predictions. Facilities have a variety of options to consider for gathering accurate weather and heat information that can be used by coaches, trainers, and officials. The first is a monitoring service that can provide location-specific notifications sent directly to officials. Another, even more accurate, option is to have a weather station installed at the facility. Using an on-site weather station offers real-time data for WBGT readings and could be a permanent or a movable unit that can be moved about as needed. There are many benefits for using an on-site weather station in addition to the WBGT readings, it offers a hyper-local forecast that provides real-time information and detail for lightning strikes, wind events, heavy rain, or tornadoes.
It’s important that extreme weather and specifically heat specifically need to be a top concern when planning for athlete safety. A recent study found that high schools still struggle with the management of exertional heat stroke and many don’t have a written heat-illness policy. Recognizing and implementing safety rules around heat stress and using the available tools such as WBGT predictions are key to keeping athletes safe during the heat of summer.
Renny Vandewege is the Vice President of Weather Operations at DTN, where he is responsible for more than 200 operational meteorologists across weather forecast rooms globally. Prior to joining the private weather industry, Renny served as the Director of the Broadcast Meteorology Program at Mississippi State University, advising and training more than 200 broadcast meteorologists in his time teaching in the program.