Medical Encounters For Cold Intolerance Among Marathon Athletes

PURPOSE: Cold intolerance, associated with environmental conditions and potential alterations in athlete thermogenesis during endurance sport, is a common but incompletely characterized clinical entity among marathon athletes. The purpose of this analysis is to characterize medical encounters (MEs) among athletes with the presenting symptom of cold intolerance. METHODS: Institutional Review Board (IRB-P00043223) and event medical program approval was obtained. Retrospective review of paper medical records was performed, and extracted data included: demographics, marathon experience, presenting complaint, vital signs, treatment, time duration of ME, and disposition. Data were transferred into a secure database (REDCap), and analyzed using SPSS. RESULTS: The 2016 Boston Marathon included 30,741 total entrants, including 14,112 women (W), and 16,629 men (M). WBGT average measured at 3 course locations was 19.6 °C at 0900, 19.0 °C at 1200, and 14.9 °C at 1500. Of 1,185 ME records reviewed, 98 entrants (W: 53, M: 45) had the presenting symptom of cold intolerance. Thus, cold intolerance was the presenting symptom for 8.3% of MEs (% of MEs W: 10.4%; M: 7.7%). Among those presenting for cold intolerance, age (mean ± SD): W: 36.9 ± 8.3 yrs; M: 40.9 ± 12.5 yrs. Prior marathon experience (median, IQR): W: 3 (1.25, 8), M: 4 (2, 8). Mean tympanic temperatures: W: 95.9 ± 1.9 °F, (range 90.7-99.5 °F); M: 95.4 ± 1.8 °F, (range 92.5-99.4 °F). Among W with cold intolerance, mean duration of ME was 39 ± 31 minutes, with 7 (13.2%) treated with external forced-air (Bair Hugger 3MTM) warmers, EKG: 1 (1.8%), labs: 4 (7.6%), and IV fluids 0 (0%). Among M with cold intolerance, mean duration of ME was 49 ± 35 minutes, with 3 (6.7%) treated with external forced-air warmers, EKG: 1 (2.2%), labs: 7 (15.6%), and IV fluids: 4 (8.9%). All athletes that presented for cold-intolerance were discharged to the event/home, none required hospital transport. CONCLUSIONS: Cold intolerance is a common presenting symptom among marathon athletes, even under moderate environmental weather conditions, including 10.4% of women and 7.7% of men with recorded MEs at the 2016 Boston Marathon. Associated medical resource demands include notable time in event medical stations, and infrequent use of labs, IV fluids, and EKGs for management of concurrent symptoms/conditions.