Heat preparedness and exertional heat illness in Paralympic athletes: A Tokyo 2020 survey

Abstract

Paralympic athletes may be at increased risk for exertional heat illness (EHI) due to reduced thermoregulatory ability as a consequence of their impairment. This study investigated the occurrence of heat-stress related symptoms and EHI, and the use of heat mitigation strategies in Paralympic athletes, both in relation to the Tokyo 2020 Paralympic Games and previous events. Paralympic athletes competing in Tokyo 2020 were invited to complete an online survey five weeks prior to the Paralympics and up to eight weeks after the Games. 107 athletes (30 [24-38] years, 52% female, 20 nationalities, 21 sports) completed the survey. 57% of respondents had previously experienced heat-stress related symptoms, while 9% had been medically diagnosed with EHI. In Tokyo, 21% experienced at least one heat-stress related symptom, while none reported an EHI. The most common symptom and EHI were, respectively, dizziness and dehydration. In preparation for Tokyo, 58% of respondents used a heat acclimation strategy, most commonly heat acclimatization, which was more than in preparation for previous events (45%; P = 0.007). Cooling strategies were used by 77% of athletes in Tokyo, compared to 66% during past events (P = 0.18). Cold towels and packs were used most commonly. Respondents reported no medically-diagnosed EHIs during the Tokyo 2020 Paralympic Games, despite the hot and humid conditions in the first seven days of competition. Heat acclimation and cooling strategies were used by the majority of athletes, with heat acclimation being adopted more often than for previous competitions.

Keywords: Heat acclimation; adapted sports; cooling; heat mitigation; impairment; para-athletes.

Figure 1.

Overview of data collection and respondent selection. EHI, exertional heat illness.

Figure 2.

Respondent characteristics (n = 107). II, intellectual impairment; SCI, spinal cord injury; VI, visual impairment.

Figure 3.

a; Schedule of the outdoor endurance events at the Tokyo 2020 Paralympic Games. b; Daily (06:00–22:00 h) meteorological data 6 days before and 12 days during the Tokyo 2020 Paralympic Games. Points and error bars represent median and interquartile range, respectively. Red flags highlight daily wet-bulb globe temperature (WBGT) medians that exceeded the “cancel level for exertional heat stroke risk” for competition as advised by The American College of Sports Medicine (>27.9°C) [43].

Figure 4.

a; Incidence of heat-stress related symptoms during past events (temperate environment [15 to 25°C] and hot environment [>25°C]) and in Tokyo. b; Incidence of specific heat-stress related symptoms during past events and in Tokyo. c; Incidence of exertional heat illness (EHI) during past events and in Tokyo. Percentages >10% are displayed in the appropriate bars.

Figure 5.

a; Prevalence of heat acclimation (HA) in preparation for past events and for Tokyo. b; Prevalence of specific HA strategies in preparation for past events and for Tokyo. Percentages >10% are displayed in the appropriate bars. HWI, hot water immersion; Room, artificial environment e.g. climate chamber or hot room.

Figure 6.

a; Prevalence of cooling strategy use during past events and in Tokyo. Cooling was used both pre- (PRE) and during (PER) competition, or only PRE or PER (small proportion not specified). b; Prevalence of specific PRE- and PER-cooling strategies during past events and in Tokyo. CWI, cold water immersion. c; Prevalence of number of different cooling strategies reported by cooling users during past events and in Tokyo. Percentages >10% are displayed in the appropriate bars.

Figure 7.

Simple logistic regression outcomes. The likelihood of the dependent variables was tested for the participant characteristics (predictor variables) shown in the table. Dependent variables were heat-coping ability rating, occurrence of heat-stress related symptoms, heat acclimation (HA) use, and cooling use in the past and in Tokyo. Green and red arrow symbols denote a higher and lower likelihood with respect to the reference variable (ref), respectively. Points and error bars represent odds ratio (OR) estimate and confidence interval (CI) on a logarithmic scale. Only outcomes with P < 0.06 are presented (significance level P < 0.05).