JOURNAL ARTICLE

Effectiveness of Ice-Sheet Cooling Following Exertional Hyperthermia

Cory L Butts, Debora L Spisla, J D Adams, Cody R Smith, Kathleen M Paulsen, Aaron R Caldwell, Matthew S Ganio, Brendon P McDermott
Military Medicine 2017, 182 (9): e1951-e1957
28885961

BACKGROUND: The procedure of wrapping a heat casualty in ice-water soaked bed sheets to reduce core temperature has received little investigation, despite the practice and recommendation for its use in some military settings. Thus, the purpose of this study was to investigate the cooling efficacy of ice-sheet cooling (ISC) following exertional hyperthermia.

METHODS: 13 (11 males, 2 females) participants (age = 23 ± 3 years, height = 176.5 ± 10.3 cm, mass = 78.6 ± 15.3 kg, body fat = 19.6 ± 8.6%, and body surface area = 1.95 ± 0.22 m2 ) volunteered to complete 2 randomized, crossover design trials on an outdoor recreation field (34.4 ± 1.4°C, 54.4 ± 4.1% relative humidity). Each trial consisted of exercise (self-paced 400-m warm-up, 1,609-m run, and 100-m sprints) followed by 15 minutes of either lying supine in the shade with no treatment (control [CON]) or being treated with ice-water soaked sheets wrapped around their body (ISC). Physiological (rectal temperature [Tre ], heart rate, mean-weighted skin temperature) and perceptual measures (thermal sensation, rating of perceived exertion) were assessed after each exercise protocol, every 3 minutes during treatment, and every 5 minutes during recovery.

FINDINGS: By design, there were no differences during exercise between ISC and CON for Tre (p = 0.16), skin temperature (p = 0.52), heart rate (p = 0.62), thermal sensation (p = 0.89), or rating of perceived exertion (p = 0.99). There were greater decreases in Tre at 3 (ISC 0.33 ± 0.26°C vs. CON 0.03 ± 0.30°C, p = 0.01) and 6 minutes (ISC 0.47 ± 0.27°C vs. CON 0.30 ± 0.19°C, p = 0.05) of treatment; however, the overall rate of cooling was not different between trials (CON 0.05 ± 0.02°C/min vs. ISC 0.06 ± 0.02°C/min, p = 0.72). Skin temperature (Tsk ) was significantly reduced from 3 minutes (ISC 34.4 ± 1.7°C vs. CON 36.6 ± 0.5°C, p = 0.007) through 15 minutes (ISC 32.4 ± 1.5 vs. CON 36.1 ± 0.4°C, p < 0.001) of treatment. There was a trend for lower heart rate with ISC (p = 0.051). Thermal sensation was reduced from 3 minutes of treatment (ISC 3.5 ± 0.9 vs. CON 4.5 ± 0.6, p = 0.002) through 15 minutes (ISC 2.8 ± 1.0 vs. CON 3.9 ± 0.4, p = 0.005).

DISCUSSION: ISC does not provide effective reduction in Tre following exertional hyperthermia compared to no treatment. However, perceptual benefits may warrant the use of ISC in settings where rapid reductions in core temperature are not a concern (i.e., recovery from exercise). Thus, clinicians should continue to utilize validated techniques (i.e., cold-water immersion) for the treatment of exertional heat illnesses.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
28885961
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"