By Yuri Hosokawa, MAT, ATC, Director of Communication, Director of Education  

Here in New England, we are starting to see the hint of fall foliage. Fall sports are in the midst of competition and athletes are not afraid to show all the hard work they have put it in throughout the summer months. The weather has cooled down considerably around Storrs, CT during the course of the last few weeks. For example, the forecast for the next few days looks like this in our region.

^{Source: weatherwunderground.com Forecast for Storrs, CT. Accessed 10/02/2016.}

During pre-season football, we had several days where the ambient temperature was greater than 90-degrees Fahrenheit. I know, I can hear the mind of fellow ATs from the southern states, “we still have days exceeding 90-degrees Fahrenheit and it’s October!”

^{Source: weatherwunderground.com Forecast for Tampa, FL. Accessed 10/02/2016.}

In 2015, Dr. Andrew Grundstein, a professor from the University of Georgia, published a paper that captures this regional differences and proposed activity guideline that takes account of the local climate. In this model, Storrs, CT is classified in Category I, which has the lower threshold to begin activity modification & event cancellation. Tampa, FL is classified in Category III, whose activity guideline closely follow the one developed by the Georgia High School Association that developed the activity guideline based on the heat related injury epidemiology data collected in Georgia.

This regional variance is expected for obvious geographical differences. Therefore, it only makes sense to know and adjust the thermal strain by what’s expected in the region. In other words, what may not be considered a “cancellation level” in the southern states may still be oppressive enough to cancel activities in the northern states, and vice versa.      

Some of you may be wondering, “it is well past beyond pre-season practices and the likelihood of experiencing oppressive heat stress is minimal.” You may be right in that it is less likely. But suppose we experience one day with temperatures exceeding 80-degrees Fahrenheit and »60% humidity in Storrs, CT. This could potentially push the wet bulb globe temperature (WBGT) to rise over 82-degrees Fahrenheit, which warrants considerable activity modification (i.e., maximum practice time 2 hours with increased frequency of rest breaks) in Category I but not necessary in Category III.

(Note: WBGT values should not be used interchangeably with Heat Index or air temperature. View a video from here to learn how these measures are different.)

A well-known example of unexpected weather during the fall is the 2007 Chicago Marathon, where the race organizers made an executive decision to shut down the race after 3.5 hours due to inclement heat (ambient temperature at 88-degrees Fahrenheit).

The 2016 Chicago Marathon is scheduled in less than a week, and as of now, the weather will likely to be cooperating with the runners.

^{Source: weatherwunderground.com Forecast for Tampa, FL. Accessed 10/02/2016.}

Now, imagine recording highs of 88-degrees Fahrenheit in Chicago, IL (more than 20-degrees higher than what is forecasted for this year’s race), which is a Category II in the 2015 paper. Although there is a limitation in estimating race day WBGT from just the air temperature, it is apparent that recording near 90-degrees Fahrenheit for air temperature, especially around this time of the year for Chicago, is beyond their regional norm. Needless to say, it would affect not only the local runners but other runners who are traveling from all over the world who did not expect the race day to be this oppressive.

At the end of the day, environmental monitoring is only one of the many tools we have to ensure safety of athletes. Monitoring the wet bulb globe temperature by itself will not protect the athletes per se, but it will give you valuable information for making a better clinical judgment in deciding to modify activity. A great thing about weather conditions is that, at most times, the weather forecast will allow you to make appropriate actions and intervene proactively to remove potential hazards (i.e., moving the event time and/or date, modifying practice intensity and/or duration).

#KnowYourCondition