The Thermal Environment

Managing the Heat in Sport

• By Ross Di Corleto
• 22/02/2015
• 4 Comments

Some time ago I posted a blog relating to the soccer World Cup series proposed in Qatar in 2022 and the potential heat issues that they may encounter. There were some very interesting discussions that followed on from this which illustrated the different way in which elite athletes cope with the heat. In a similar theme, a colleague of mine recently directed my attention to an interesting document from the Climate Institute called “Sport and climate impacts: How much heat can sport handle?” Reading it raised some interesting questions for me around how we are actually managing the issue of heat exposure at all levels of sport, particularly in Australia.

What struck me the most was that in a country where we engage in so many outdoor sports in warm climates and often in the height of summer, how little we have in the way of a co-ordinated formal policy and guidance. What is also noticeable is the significant variation in how different sporting bodies are managing the heat issue. What can be said is that in many cases we are not doing it well. I have to admit I have a concern as to whether there is an understanding of the significance of the variability of the different parameters relating to the climate and of the impacts. What we are seeing is that in many cases where guidance does exist, a number of the sporting bodies have opted to use the air temperature as their limit or action level. Now using just the air temperature for heat stress management is like setting the road alcohol level to five alcoholic drinks and not considering individuals weight, size of each drink, percentage of alcohol etc etc. It is not going to work!

The impact of heat is dependent on many factors in the climate such as humidity, air velocity and radiant heat, not to mention the numerous physiological variables associated with the individuals that are exposed to the heat. How do you compare the impact of a 37°C air temperature scenario on an elite athlete, a junior player, umpires/officials or for that matter the 50+ year old not so elite 130 kg spectator sitting in the sun in the stands downing a few beers? One size doesn’t fit all.

It is great to see some of the local and international sporting bodies (Australian Tennis Open, American College of Sports Medicine) have moved towards the use of a heat stress index that takes into consideration more of the climatic variables. In most cases this appears to be the Wet Bulb Globe Temperature (WBGT) but there also needs to be care taken here, as the use of the WBGT can be fraught with pitfalls if used incorrectly. It is not as simple as it appears as there are a number of different considerations and conditions associated with its use. The other aspect to bear in mind is that there are a number of studies in the literature (Pulket, 1980; Budd, 2008; d’Ambrosio Alfano, 2014) that have shown WBGT to be sadly lacking in some aspects particularly in hot humid conditions. There are other more modern indices that can be utilised to help model potential climatic issues with a greater level of confidence but they do require additional information relating to the individuals such as clothing, approximate weight and level of activity.

The selection and use of heat stress indices is a whole other story which we wont cover here. Suffice it to say that whatever index is chosen it should only be ever used as a guideline NEVER as a safe unsafe limit. We are in need of some formal guidance material that is clear and practical to make sure we are protecting the many individuals who participate in one form or another in sporting events in our great outdoors. We do it in industry so why not for sport?

So what is the right approach? I can’t give you the answer here in this short blog but we need to start taking the issue a bit more seriously and putting our heads together to come up with some clear guidance and communicate it better at all levels of sport.

BOTTOM LINE

It is great to see the rising awareness of the heat issue in sport but we are in need of some clear formal guidance material for use at the many types of sporting events that are run in this country. Something practical but based on solid science that will help protect all participants.

WANT TO KNOW MORE?

The Climate Institute (2014). Sport and climate impacts: How much heat can sport handle? Accessed on 06/02/2015 at http://www.climateinstitute.org.au/sport-and-climate.html

American College of Sports Medicine. (1985) Position stand on the prevention of thermal injuries during distance running.

Pulket, C., Henshel, A., et al (1980). “A Comparison of Heat Stress Indices in a Hot-Humid Environment”. Am. Ind. Hy. Assoc. J., 41, p447 – 449

Budd, GM (2008). Wet-bulb globe temperature (WBGT) – Its history and its limitations. J Science & Med in Sport, 11: pp 20-32.

D’Ambrosio Alfano, F. R., Malchaire, J., Palella, B.I., Riccio, G., (2014). WBGT Index revisited after 60 years of use. Ann. Occup.Hyg., Vol. 58, No. 8, 955-970