Exertional heat stroke. Are we cool enough? Retrospective observational study of patients of running events

Background
Early recognition and immediate cooling are paramount in the treatment for exertional heat stroke (EHS). The most effective method is cold water immersion, however, practicalities may limit its use in the prehospital setting. An alternative is rotating ice water–soaked towels, which requires fewer personnel, can be deployed quickly, and allows easier patient monitoring.

Objective
The authors aimed to investigate the effectiveness of treatment with rotating ice water–soaked towels for patients with EHS to reduce (tympanic) temperature to < 104°F (40°C) within 30 min.

Methods
In this retrospective observational study, participants ≥18 years who received medical care at running events with distances between 2.6 mile (4.2 km) and 26.2 miles (42.195 km; i.e., a full marathon) between 2016 and 2019 were included. Primary outcome was the percentage of patients with EHS who reached a temperature < 104°F (40°C) within 30 min by means of cooling with rotating ice water–soaked towels.

Results
A total of 374,534 runners participated in one of the running events in the study period, of whom 879 required medical attention. Forty-eight runners had a tympanic temperature ≥ 104°F (40°C), of whom 36 were classified as having EHS based on presence of neurologic symptoms. Median age of patients was 32.5 years and most were male (69%). All patients that were cooled reached temperature < 104°F (40°C) within 30 min. The mean cooling rate was 0.22°F/min (95% CI 0.16–0.27; 0.12°C/min [95% CI 0.09–0.15]). None of the patients with EHS died.

Conclusions
All patients with EHS in our study reached a temperature of < 104°F (40°C) within 30 min, which suggests rotating ice water–soaked towels could provide an effective and practical method of cooling in the prehospital setting.