A retrospective analysis of American football hyperthermia deaths in the United States

Abstract

Over the period 1980-2009, there were 58 documented hyperthermia deaths of American-style football players in the United States. This study examines the geography, timing, and meteorological conditions present during the onset of hyperthermia, using the most complete dataset available. Deaths are concentrated in the eastern quadrant of the United States and are most common during August. Over half the deaths occurred during morning practices when high humidity levels were common. The athletes were typically large (79% with a body mass index >30) and mostly (86%) played linemen positions. Meteorological conditions were atypically hot and humid by local standards on most days with fatalities. Further, all deaths occurred under conditions defined as high or extreme by the American College of Sports Medicine using the wet bulb globe temperature (WBGT), but under lower threat levels using the heat index (HI). Football-specific thresholds based on clothing (full football uniform, practice uniform, or shorts) were also examined. The thresholds matched well with data from athletes wearing practice uniforms but poorly for those in shorts only. Too few cases of athletes in full pads were available to draw any broad conclusions. We recommend that coaches carefully monitor players, particularly large linemen, early in the pre-season on days with wet bulb globe temperatures that are categorized as high or extreme. Also, as most of the deaths were among young athletes, longer acclimatization periods may be needed.

Impact of Extreme Heat Events on Emergency Department Visits in North Carolina (2007–2011)

“…Examination of available triage notes in the NC DETECT dataset revealed that [40 % of HRI visits were associated with exercise or recreation, of which two-thirds were linked to organized sports among 10-18 year olds [17]. Football players are particularly vulnerable to HRI due to uniform requirements and physiological characteristics that increase metabolic heat production and storage [39,40]. These risk factors are especially evident during pre-season practices (usually in late July and early August) when players are not yet acclimatized to performing in high heat and humidity [41].…”

Regional heat safety thresholds for athletics in the contiguous United States

“…Indeed, Cooper, Ferrara, and Broglio (2006) identified elevated heat injuries among football players with increased heat exposure. Similarly, Grundstein et al (2012) found that the vast majority of football hyperthermia deaths occurred during weather that was unusually hot and humid by local standards.…”

Heat-Related Deaths in American Football: An Interdisciplinary Approach

“…For example, researchers have identified where and when heat-related deaths primarily occur: they are most common in the southeastern quadrant of the United States during the month of August, when high temperatures combine with a range of meteorological conditions that must dictate the intensity, and even the possibility, of staging of a football session.75 More than half of all fatalities happen during a morning practice with high levels of humidity, which impedes sweat dissipation, a process that cools the skin and helps restore heat balance. 76 Statistics show that 97 per cent of heat-related deaths happen because of practice sessions; 87 per cent of those deaths came as a result of two-a-day sessions; 60 per cent occurred in players wearing helmets; and 50 per cent happen on the first day of the season.77 Taken together, these findings indicate that many players may not be properly acclimatized when they first take the field-that they may not be "heat fit"-and there is now a clear and substantiated collection of best-practice policies that any coach can readily access. 78 Researchers also know that bigger football players are more susceptible to the problem.…”