Safe cooling limits from exercise-induced hyperthermia

Proulx, Caroline; Ducharme, Michel B.; Kenny, Glen P.

doi:10.1007/s00421-005-0063-y

Cited by 68 publications

(75 citation statements)

References 36 publications

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“…4,5 Faster cooling rates have been observed with colder water and large skin-surface immersion. 1,9,10 Cooling rates of EHS patients using CWI (0.228C/ min) 5 demonstrate consistency with those reported in hyperthermic research participants (0.198C/min). 3 Unfortunately, a large tub for CWI may not be available at all facilities due to monetary or spatial restrictions.…”

supporting

confidence: 60%

“…An effective EHS treatment puts the greatest possible skin surface area in contact with water and provides a temperature gradient facilitating rapid heat exchange. 9,10 Colder water temperatures (28C) during CWI have resulted in the fastest cooling rates with a continuing afterdrop in T re following removal. 9,10 When water temperatures are similar to ours (208C), CWI facilitates much faster cooling with a rate of 0.198C/min.…”

Section: Discussionmentioning

confidence: 99%

“…[17][18][19] This is also true of CWI, but the larger surface area contact and constant water movement to accentuate convective heat loss augments heat transfer. 9,10,17 Therefore, the amount of surface area contacted during CS may not be large enough to offset cold-induced vasoconstriction, resulting in attenuated heat transfer and cooling.…”

Section: Discussionmentioning

confidence: 99%

“…9,10 Colder water temperatures (28C) during CWI have resulted in the fastest cooling rates with a continuing afterdrop in T re following removal. 9,10 When water temperatures are similar to ours (208C), CWI facilitates much faster cooling with a rate of 0.198C/min. 9 Thus, it is likely that the slow cooling rate of the CS in the present study (0.078C/min) is not attributable solely to water temperature.…”

Section: Discussionmentioning

confidence: 99%

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Physiologic and Perceptual Responses to Cold-Shower Cooling After Exercise-Induced Hyperthermia

Butts

McDermott

Buening

et al. 2016

Journal of Athletic Training

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Context: Exercise conducted in hot, humid environments increases the risk for exertional heat stroke (EHS). The current recommended treatment of EHS is cold-water immersion; however, limitations may require the use of alternative resources such as a cold shower (CS) or dousing with a hose to cool EHS patients.Objective: To investigate the cooling effectiveness of a CS after exercise-induced hyperthermia.Design: Randomized, crossover controlled study. Setting: Environmental chamber (temperature ¼ 33.48C 6 2.18C; relative humidity ¼ 27.1% 6 1.4%).Patients or Other Participants: Seventeen participants (10 male, 7 female; height ¼ 1.75 6 0.07 m, body mass ¼ 70.4 6 8.7 kg, body surface area ¼ 1.85 6 0.13 m 2 , age range ¼ 19-35 years) volunteered.Intervention(s): On 2 occasions, participants completed matched-intensity volitional exercise on an ergometer or treadmill to elevate rectal temperature to 398C or until participant fatigue prevented continuation (reaching at least 38.58C). They were then either treated with a CS (20.88C 6 0.808C) or seated in the chamber (control [CON] condition) for 15 minutes.Main Outcome Measure(s): Rectal temperature, calculated cooling rate, heart rate, and perceptual measures (thermal sensation and perceived muscle pain).Results: The rectal temperature (P¼ .98), heart rate (P¼ .85), thermal sensation (P ¼ .69), and muscle pain (P ¼ .31) were not different during exercise for the CS and CON trials (P . .05). Overall, the cooling rate was faster during CS (0.078C/min 6 0.038C/min) than during CON (0.048C/min 6 0.038C/min; t 16 ¼ 2.77, P ¼ .01). Heart-rate changes were greater during CS (45 6 20 beats per minute) compared with CON (27 6 10 beats per minute; t 16 ¼ 3.32, P ¼ .004). Thermal sensation was reduced to a greater extent with CS than with CON (F 3,45 ¼ 41.12, P , .001).Conclusions: Although the CS facilitated cooling rates faster than no treatment, clinicians should continue to advocate for accepted cooling modalities and use CS only if no other validated means of cooling are available.Key Words: heat stress, exertional heat illness, whole-body cooling, water dousing Key PointsThe use of a cold shower to treat exertional hyperthermia was more effective than no treatment. The cooling rates elicited via the cold shower technique were deemed unacceptable when compared with the goldstandard treatment of cold-water immersion. Clinicians should continue to advocate for appropriate cold-water immersion resources. However, if cold-water immersion is not available, the cold shower technique should be used to treat patients with exertional heat illness as a last resort.

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supporting

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Physiologic and Perceptual Responses to Cold-Shower Cooling After Exercise-Induced Hyperthermia

Butts

McDermott

Buening

et al. 2016

Journal of Athletic Training

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“…28,29,31 By comparison, T rec cooling rates of hyperthermic humans undergoing CWI range from 0.128CÁmin À1 to 0.358CÁmin À1 . 14,29,30,32À35 The faster T eso cooling rates can be explained by less organ mass and density in the thorax compared with the gut 14 and rapid incorporation of cooled blood from the periphery into the general circulation.…”

mentioning

confidence: 99%

Validity of Core Temperature Measurements at 3 Rectal Depths During Rest, Exercise, Cold-Water Immersion, and Recovery

Miller

Hughes

Long

et al. 2017

Journal of Athletic Training

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Context: No evidence-based recommendation exists regarding how far clinicians should insert a rectal thermistor to obtain the most valid estimate of core temperature. Knowing the validity of temperatures at different rectal depths has implications for exertional heat-stroke (EHS) management.Objective: To determine whether rectal temperature (T rec ) taken at 4 cm, 10 cm, or 15 cm from the anal sphincter provides the most valid estimate of core temperature (as determined by esophageal temperature [T eso ]) during similar stressors an athlete with EHS may experience.Design: Cross-sectional study. Setting: Laboratory.Patients or Other Participants: Seventeen individuals (14 men, 3 women: age ¼ 23 6 2 years, mass ¼ 79.7 6 12.4 kg, height ¼ 177.8 6 9.8 cm, body fat ¼ 9.4% 6 4.1%, body surface area ¼ 1.97 6 0.19 m 2 ). Intervention(s): Rectal temperatures taken at 4 cm, 10 cm, and 15 cm from the anal sphincter were compared with T eso during a 10-minute rest period; exercise until the participant's T eso reached 39.58C; cold-water immersion (~108C) until all temperatures were 388C; and a 30-minute postimmersion recovery period. The T eso and T rec were compared every minute during rest and recovery. Because exercise and cooling times varied, we compared temperatures at 10% intervals of total exercise and cooling durations for these periods.Main Outcome Measure(s): The T eso and T rec were used to calculate bias (ie, the difference in temperatures between sites).Results: Rectal depth affected bias (F 2,24 ¼ 6.8, P ¼ .008). Bias at 4 cm (0.858C 6 0.788C) was higher than at 15 cm (0.658C 6 0.688C, P , .05) but not higher than at 10 cm (0.758C 6 0.768C, P . .05). Bias varied over time (F 2,34 ¼ 79.5, P , .001). Bias during rest (0.428C 6 0.278C), exercise (0.238C 6 0.538C), and recovery (0.658C 6 0.358C) was less than during cooling (1.728C 6 0.658C, P , .05). Bias during exercise was less than during postimmersion recovery (0.658C 6 0.358C, P , .05).Conclusions: When EHS is suspected, clinicians should insert the flexible rectal thermistor to 15 cm (6 in) because it is the most valid depth. The low level of bias during exercise suggests T rec is valid for diagnosing hyperthermia. Rectal temperature is a better indicator of pelvic organ temperature during cold-water immersion than is T eso .

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