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. 2021 Sep 1;53(9):1818-1825.
doi: 10.1249/MSS.0000000000002652.

Exertional Heat Stroke at the Boston Marathon: Demographics and the Environment

Rebecca G Breslow, Jamie E Collins, Chris Troyanos, Mylan C Cohen, Pierre D'Hemecourt, K Sophia Dyer  1 , Aaron Baggish
Affiliations

Exertional Heat Stroke at the Boston Marathon: Demographics and the Environment

Rebecca G Breslow et al. Med Sci Sports Exerc. .

Abstract

Purpose: This study aimed to assess associations between exertional heat stroke (EHS) and sex, age, prior performance, and environmental conditions, and report on resources needed for EHS cases at the Boston Marathon.

Methods: We analyzed participant characteristics, environmental data, and EHS medical encounters during the 2015-2019 Boston Marathon races.

Results: Among 136,161 starters, there was an incidence of 3.7 EHS cases per 10,000 starters (95% confidence interval, 2.8-4.9), representing 0.5% of all medical encounters. There were significant associations between sex and age (P < 0.0001), sex and start wave (P < 0.0001), and age group and start wave (P < 0.0001). Sex was not significantly associated with increased EHS incidence; however, age younger than 30 yr and assignment to the first two start waves were. All cases occurred at races with average wet bulb globe temperatures of 17°C-20°C. There was a linear correlation between EHS incidence and greater increases in wet bulb globe temperature from start to peak (R2 = 0.7688). A majority of cases (37; 72.5%) were race finishers; nonfinishers all presented after mile 18. Most were triaged 3-4 h after starting, and all were treated with ice water immersion. Treatment times were prolonged (mean (SD), 78.1 (47.5) min; range, 15-190 min); 29.4% (15 cases) developed posttreatment hypothermia, and 35.3% (18 cases) were given intravenous fluids. Most (31 cases; 64.6%) were discharged directly, although 16 cases (33.3%) required hospital transport. There were no fatalities.

Conclusions: Younger and faster runners are at higher risk for EHS at the Boston Marathon. Greater increases in heat stress from start to peak during a marathon may exacerbate risk. EHS encounters comprise a small percentage of race-day medical encounters but require extensive resources and warrant risk mitigation efforts.

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References

    1. Armstrong LE, Casa DJ, Millard-Stafford M, Moran DS, Pyne SW, Roberts WOAmerican College of Sports Medicine. American College of Sports Medicine Position Stand. Exertional heat illness during training and competition. Med Sci Sports Exerc . 2007;39(3):556–72.
    1. DeMartini JK, Casa DJ, Belval LN, et al. Environmental conditions and the occurrence of exertional heat illnesses and exertional heat stroke at the Falmouth Road race. J Athl Train . 2014;49(4):478–85.
    1. Hosokawa Y, Adams WM, Belval LN, et al. Exertional heat illness incidence and on-site medical team preparedness in warm weather. Int J Biometeorol . 2018;62(7):1147–53.
    1. Grundstein AJ, Hosokawa Y, Casa DJ, Stearns RL, Jardine JF. Influence of race performance and environmental conditions on exertional heat stroke prevalence among runners participating in a warm weather road race. Front Sports Act Living . 2019;1:42.
    1. Breslow RG, Shrestha S, Feroe AG, Katz JN, Troyanos C, Collins JE. Medical tent utilization at 10-km road races: injury, illness, and influencing factors. Med Sci Sports Exerc . 2019;51(12):2451–7.

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