Chemically Activated Cooling Vest’s Effect on Cooling Rate Following Exercise-Induced Hyperthermia: A Randomized Counter-Balanced Crossover Study

Background and objectives: Exertional heat stroke (EHS) is a potentially lethal, hyperthermic condition that warrants immediate cooling to optimize the patient outcome. The study aimed to examine if a portable cooling vest meets the established cooling criteria (0.15 °C·min−1 or greater) for EHS treatment. It was hypothesized that a cooling vest will not meet the established cooling criteria for EHS treatment. Materials and Methods: Fourteen recreationally active participants (mean ± SD; male, n = 8; age, 25 ± 4 years; body mass, 86.7 ± 10.5 kg; body fat, 16.5 ± 5.2%; body surface area, 2.06 ± 0.15 m2. female, n = 6; 22 ± 2 years; 61.3 ± 6.7 kg; 22.8 ± 4.4%; 1.66 ± 0.11 m2) exercised on a motorized treadmill in a hot climatic chamber (ambient temperature 39.8 ± 1.9 °C, relative humidity 37.4 ± 6.9%) until they reached rectal temperature (TRE) >39 °C (mean TRE, 39.59 ± 0.38 °C). Following exercise, participants were cooled using either a cooling vest (VEST) or passive rest (PASS) in the climatic chamber until TRE reached 38.25 °C. Trials were assigned using randomized, counter-balanced crossover design. Results: There was a main effect of cooling modality type on cooling rates (F[1, 24] = 10.46, p < 0.01, η2p = 0.30), with a greater cooling rate observed in VEST (0.06 ± 0.02 °C·min−1) than PASS (0.04 ± 0.01 °C·min−1) (MD = 0.02, 95% CI = [0.01, 0.03]). There were also main effects of sex (F[1, 24] = 5.97, p = 0.02, η2p = 0.20) and cooling modality type (F[1, 24] = 4.38, p = 0.047, η2p = 0.15) on cooling duration, with a faster cooling time in female (26.9 min) than male participants (42.2 min) (MD = 15.3 min, 95% CI = [2.4, 28.2]) and faster cooling duration in VEST than PASS (MD = 13.1 min, 95% CI = [0.2, 26.0]). An increased body mass was associated with a decreased cooling rate in PASS (r = −0.580, p = 0.03); however, this association was not significant in vest (r = −0.252, p = 0.39). Conclusions: Although VEST exhibited a greater cooling capacity than PASS, VEST was far below an acceptable cooling rate for EHS treatment. VEST should not replace immediate whole-body cold-water immersion when EHS is suspected.

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

Journal of Athletic Training ◽

10.4085/1062-6050-51.4.01 ◽

2016 ◽

Vol 51 (3) ◽

pp. 252-257 ◽

Cited By ~ 11

Author(s):

Cory L. Butts ◽

Brendon P. McDermott ◽

Brian J. Buening ◽

Jeffrey A. Bonacci ◽

Matthew S. Ganio ◽

...

Keyword(s):

Heart Rate ◽

Cooling Rate ◽

Rectal Temperature ◽

Muscle Pain ◽

Cold Water ◽

Thermal Sensation ◽

Water Immersion ◽

Heat Stroke ◽

Cold Water Immersion ◽

Exercise Induced

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.Context: To investigate the cooling effectiveness of a CS after exercise-induced hyperthermia.Objective: Randomized, crossover controlled study.Design: Environmental chamber (temperature = 33.4°C ± 2.1°C; relative humidity = 27.1% ± 1.4%).Setting: Seventeen participants (10 male, 7 female; height = 1.75 ± 0.07 m, body mass = 70.4 ± 8.7 kg, body surface area = 1.85 ± 0.13 m2, age range = 19–35 years) volunteered.Patients or Other Participants: On 2 occasions, participants completed matched-intensity volitional exercise on an ergometer or treadmill to elevate rectal temperature to ≥39°C or until participant fatigue prevented continuation (reaching at least 38.5°C). They were then either treated with a CS (20.8°C ± 0.80°C) or seated in the chamber (control [CON] condition) for 15 minutes.Intervention(s): Rectal temperature, calculated cooling rate, heart rate, and perceptual measures (thermal sensation and perceived muscle pain).Main Outcome Measure(s): The rectal temperature (P = .98), heart rate (P = .85), thermal sensation (P = .69), and muscle pain (P = .31) were not different during exercise for the CS and CON trials (P > .05). Overall, the cooling rate was faster during CS (0.07°C/min ± 0.03°C/min) than during CON (0.04°C/min ± 0.03°C/min; t16 = 2.77, P = .01). Heart-rate changes were greater during CS (45 ± 20 beats per minute) compared with CON (27 ± 10 beats per minute; t16 = 3.32, P = .004). Thermal sensation was reduced to a greater extent with CS than with CON (F3,45 = 41.12, P < .001).Results: 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.Conclusions:

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Cooling Effectiveness of a Modified Cold-Water Immersion Method After Exercise-Induced Hyperthermia

Journal of Athletic Training ◽

10.4085/1062-6050-51.12.07 ◽

2016 ◽

Vol 51 (11) ◽

pp. 946-951 ◽

Cited By ~ 22

Author(s):

Katherine E. Luhring ◽

Cory L. Butts ◽

Cody R. Smith ◽

Jeffrey A. Bonacci ◽

Ramon C. Ylanan ◽

...

Keyword(s):

Heart Rate ◽

Mean Arterial Pressure ◽

Arterial Pressure ◽

Effect Size ◽

Cold Water ◽

Water Immersion ◽

Heat Stroke ◽

Cold Water Immersion ◽

Whole Body ◽

Exertional Heat Stroke

Context: Recommended treatment for exertional heat stroke includes whole-body cold-water immersion (CWI). However, remote locations or monetary or spatial restrictions can challenge the feasibility of CWI. Thus, the development of a modified, portable CWI method would allow for optimal treatment of exertional heat stroke in the presence of these challenges. Objective: To determine the cooling rate of modified CWI (tarp-assisted cooling with oscillation [TACO]) after exertional hyperthermia. Design: Randomized, crossover controlled trial. Setting: Environmental chamber (temperature = 33.4°C ± 0.8°C, relative humidity = 55.7% ± 1.9%). Patients or Other Participants: Sixteen volunteers (9 men, 7 women; age = 26 ± 4.7 years, height = 1.76 ± 0.09 m, mass = 72.5 ± 9.0 kg, body fat = 20.7% ± 7.1%) with no history of compromised thermoregulation. Intervention(s): Participants completed volitional exercise (cycling or treadmill) until they demonstrated a rectal temperature (Tre) ≥39.0°C. After exercise, participants transitioned to a semirecumbent position on a tarp until either Tre reached 38.1°C or 15 minutes had elapsed during the control (no immersion [CON]) or TACO (immersion in 151 L of 2.1°C ± 0.8°C water) treatment. Main Outcome Measure(s): The Tre, heart rate, and blood pressure (reported as mean arterial pressure) were assessed precooling and postcooling. Statistical analyses included repeated-measures analysis of variance with appropriate post hoc t tests and Bonferroni correction. Results: Before cooling, the Tre was not different between conditions (CON: 39.27°C ± 0.26°C, TACO: 39.30°C ± 0.39°C; P = .62; effect size = −0.09; 95% confidence interval [CI] = −0.2, 0.1). At postcooling, the Tre was decreased in the TACO (38.10°C ± 0.16°C) compared with the CON condition (38.74°C ± 0.38°C; P < .001; effect size = 2.27; 95% CI = 0.4, 0.9). The rate of cooling was greater during the TACO (0.14 ± 0.06°C/min) than the CON treatment (0.04°C/min ± 0.02°C/min; t15 = −8.84; P < .001; effect size = 2.21; 95% CI = −0.13, −0.08). These differences occurred despite an insignificant increase in fluid consumption during exercise preceding CON (0.26 ± 0.29 L) versus TACO (0.19 ± 0.26 L; t12 = 1.73; P = .11; effect size = 0.48; 95% CI = −0.02, 0.14) treatment. Decreases in heart rate did not differ between the TACO and CON conditions (t15 = −1.81; P = .09; effect size = 0.45; 95% CI = −22, 2). Mean arterial pressure was greater at postcooling with TACO (84.2 ± 6.6 mm Hg) than with CON (67.0 ± 9.0 mm Hg; P < .001; effect size = 2.25; 95% CI = 13, 21). Conclusions: The TACO treatment provided faster cooling than did the CON treatment. When location, monetary, or spatial restrictions are present, TACO represents an effective alternative to traditional CWI in the emergency treatment of patients with exertional hyperthermia.

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Acute Whole-Body Cooling for Exercise-Induced Hyperthermia: A Systematic Review

Journal of Athletic Training ◽

10.4085/1062-6050-44.1.84 ◽

2009 ◽

Vol 44 (1) ◽

pp. 84-93 ◽

Cited By ~ 105

Author(s):

Brendon P. McDermott ◽

Douglas J. Casa ◽

Matthew S. Ganio ◽

Rebecca M. Lopez ◽

Susan W. Yeargin ◽

...

Keyword(s):

Cold Water ◽

Water Immersion ◽

Cold Water Immersion ◽

Whole Body ◽

Original Research ◽

Induced Hyperthermia ◽

Body Cooling ◽

Exercise Induced ◽

Whole Body Cooling ◽

Ice Water

Abstract Objective: To assess existing original research addressing the efficiency of whole-body cooling modalities in the treatment of exertional hyperthermia. Data Sources: During April 2007, we searched MEDLINE, EMBASE, Scopus, SportDiscus, CINAHL, and Cochrane Reviews databases as well as ProQuest for theses and dissertations to identify research studies evaluating whole-body cooling treatments without limits. Key words were cooling, cryotherapy, water immersion, cold-water immersion, ice-water immersion, icing, fanning, bath, baths, cooling modality, heat illness, heat illnesses, exertional heatstroke, exertional heat stroke, heat exhaustion, hyperthermia, hyperthermic, hyperpyrexia, exercise, exertion, running, football, military, runners, marathoner, physical activity, marathoning, soccer, and tennis. Data Synthesis: Two independent reviewers graded each study on the Physiotherapy Evidence Database (PEDro) scale. Seven of 89 research articles met all inclusion criteria and a minimum score of 4 out of 10 on the PEDro scale. Conclusions: After an extensive and critical review of the available research on whole-body cooling for the treatment of exertional hyperthermia, we concluded that ice-water immersion provides the most efficient cooling. Further research comparing whole-body cooling modalities is needed to identify other acceptable means. When ice-water immersion is not possible, continual dousing with water combined with fanning the patient is an alternative method until more advanced cooling means can be used. Until future investigators identify other acceptable whole-body cooling modalities for exercise-induced hyperthermia, ice-water immersion and cold-water immersion are the methods proven to have the fastest cooling rates.

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Cold-Water Immersion Cooling Rates in Football Linemen and Cross-Country Runners With Exercise-Induced Hyperthermia

Journal of Athletic Training ◽

10.4085/1062-6050-52.7.08 ◽

2017 ◽

Vol 52 (10) ◽

pp. 902-909 ◽

Cited By ~ 1

Author(s):

Sandra Fowkes Godek ◽

Katherine E. Morrison ◽

Gregory Scullin

Keyword(s):

Cooling Rate ◽

Body Mass ◽

Body Fat ◽

Cold Water ◽

Water Immersion ◽

Cold Water Immersion ◽

Physical Characteristics ◽

Cooling Rates ◽

Cross Country ◽

Cross Country Runners

Context: Ideal and acceptable cooling rates in hyperthermic athletes have been established in average-sized participants. Football linemen (FBs) have a small body surface area (BSA)-to-mass ratio compared with smaller athletes, which hinders heat dissipation. Objective: To determine cooling rates using cold-water immersion in hyperthermic FBs and cross-country runners (CCs). Design: Cohort study. Setting: Controlled university laboratory. Patients or Other Participants: Nine FBs (age = 21.7 ± 1.7 years, height = 188.7 ± 4 cm, mass = 128.1 ± 18 kg, body fat = 28.9% ± 7.1%, lean body mass [LBM] = 86.9 ± 19 kg, BSA = 2.54 ± 0.13 m2, BSA/mass = 201 ± 21.3 cm2/kg, and BSA/LBM = 276.4 ± 19.7 cm2/kg) and 7 CCs (age = 20 ± 1.8 years, height = 176 ± 4.1 cm, mass = 68.7 ± 6.5 kg, body fat = 10.2% ± 1.6%, LBM = 61.7 ± 5.3 kg, BSA = 1.84 ± 0.1 m2, BSA/mass = 268.3 ± 11.7 cm2/kg, and BSA/LBM = 298.4 ± 11.7 cm2/kg). Intervention(s): Participants ingested an intestinal sensor, exercised in a climatic chamber (39°C, 40% relative humidity) until either target core temperature (Tgi) was 39.5°C or volitional exhaustion was reached, and were immediately immersed in a 10°C circulated bath until Tgi declined to 37.5°C. A general linear model repeated-measures analysis of variance and independent t tests were calculated, with P < .05. Main Outcome Measure(s): Physical characteristics, maximal Tgi, time to reach 37.5°C, and cooling rate. Results: Physical characteristics were different between groups. No differences existed in environmental measures or maximal Tgi (FBs = 39.12°C ± 0.39°C, CCs = 39.38°C ± 0.19°C; P = .12). Cooling times required to reach 37.5°C (FBs = 11.4 ± 4 minutes, CCs = 7.7 ± 0.06 minutes; P < .002) and therefore cooling rates (FBs = 0.156°C·min−1 ± 0.06°C·min−1, CCs = .255°C·min−1 ± 0.05°C·min−1; P < .002) were different. Strong correlations were found between cooling rate and body mass (r = −0.76, P < .001), total BSA (r = −0.74, P < .001), BSA/mass (r = 0.73, P < .001), LBM/mass (r = 0.72, P < .002), and LBM (r = −0.72, P < .002). Conclusions: With cold-water immersion, the cooling rate in CCs (0.255°C·min−1) was greater than in FBs (0.156°C·min−1); however, both were considered ideal (≥0.155°C·min−1). Athletic trainers should realize that it likely takes considerably longer to cool large hyperthermic American-football players (>11 minutes) than smaller, leaner athletes (7.7 minutes). Cooling rates varied widely from 0.332°C·min−1 in a small runner to only 0.101°C·min−1 in a lineman, supporting the use of rectal temperature for monitoring during cooling.

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Recovery From Exercise-Induced Muscle Damage: Cold-Water Immersion Versus Whole-Body Cryotherapy

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0186 ◽

2017 ◽

Vol 12 (3) ◽

pp. 402-409 ◽

Cited By ~ 18

Author(s):

Abd-Elbasset Abaïdia ◽

Julien Lamblin ◽

Barthélémy Delecroix ◽

Cédric Leduc ◽

Alan McCall ◽

...

Keyword(s):

Muscle Damage ◽

Cold Water ◽

Water Immersion ◽

Cold Water Immersion ◽

Whole Body ◽

Countermovement Jump ◽

Jump Performance ◽

Physically Active ◽

Exercise Induced ◽

Whole Body Cryotherapy

Purpose:To compare the effects of cold-water immersion (CWI) and whole-body cryotherapy (WBC) on recovery kinetics after exercise-induced muscle damage.Methods:Ten physically active men performed single-leg hamstring eccentric exercise comprising 5 sets of 15 repetitions. Immediately postexercise, subjects were exposed in a randomized crossover design to CWI (10 min at 10°C) or WBC (3 min at –110°C) recovery. Creatine kinase concentrations, knee-flexor eccentric (60°/s) and posterior lower-limb isometric (60°) strength, single-leg and 2-leg countermovement jumps, muscle soreness, and perception of recovery were measured. The tests were performed before and immediately, 24, 48, and 72 h after exercise.Results:Results showed a very likely moderate effect in favor of CWI for single-leg (effect size [ES] = 0.63; 90% confidence interval [CI] = –0.13 to 1.38) and 2-leg countermovement jump (ES = 0.68; 90% CI = –0.08 to 1.43) 72 h after exercise. Soreness was moderately lower 48 h after exercise after CWI (ES = –0.68; 90% CI = –1.44 to 0.07). Perception of recovery was moderately enhanced 24 h after exercise for CWI (ES = –0.62; 90% CI = –1.38 to 0.13). Trivial and small effects of condition were found for the other outcomes.Conclusions:CWI was more effective than WBC in accelerating recovery kinetics for countermovement-jump performance at 72 h postexercise. CWI also demonstrated lower soreness and higher perceived recovery levels across 24–48 h postexercise.

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Cooling Capacity of Transpulmonary Cooling and Cold-Water Immersion After Exercise-Induced Hyperthermia

Journal of Athletic Training ◽

10.4085/1062-6050-0146.20 ◽

2021 ◽

Vol 56 (4) ◽

pp. 383-388

Author(s):

William M. Adams ◽

Erin E. Butke ◽

Junyong Lee ◽

Mitchell E. Zaplatosch

Keyword(s):

Cold Water ◽

Water Immersion ◽

Heat Stroke ◽

Cooling Capacity ◽

Cold Water Immersion ◽

Peak Oxygen Uptake ◽

Treatment Modalities ◽

Controlled Clinical Trial ◽

Cooling Rates ◽

Adjunct Treatment

Context Cold-water immersion (CWI) may not be feasible in some remote settings, prompting the identification of alternative cooling methods as adjunct treatment modalities for exertional heat stroke (EHS). Objective To determine the differences in cooling capacities between CWI and the inhalation of cooled air. Design Randomized controlled clinical trial. Setting Laboratory. Patients or Other Participants A total of 12 recreationally active participants (7 men, 5 women; age = 26 ± 4 years, height = 170.6 ± 10.1 cm, mass = 76.0 ± 18.0 kg, body fat = 18.5% ± 9.7%, peak oxygen uptake = 42.7 ± 8.9 mL·kg−1·min−1). Intervention(s) After exercise in a hot environment (40°C and 40% relative humidity), participants were randomized to 3 cooling conditions: cooling during passive rest (PASS; control), CWI, and the Polar Breeze thermal rehabilitation machine (PB) with which participants inspired cooled air (22.2°C ± 1.0°C). Main Outcome Measure(s) Rectal temperature (TREC) and heart rate were continuously measured throughout cooling until TREC reached 38.25°C. Results Cooling rates during CWI (0.18°C·min−1 ± 0.06°C·min−1) were greater than those during PASS (mean difference [95% CI] of 0.16°C·min−1 [0.13°C·min−1, 0.19°C·min−1]; P < .001) and PB (0.15°C·min−1 [0.12°C·min−1, 0.16°C·min−1]; P < .001). Elapsed time to reach a TREC of 38.25°C was also faster with CWI (9.71 ± 3.30 minutes) than PASS (−58.1 minutes [−77.1, −39.9 minutes]; P < .001) and PB (−46.8 minutes [−65.5, −28.2 minutes]; P < .001). Differences in cooling rates and time to reach a TREC of 38.25°C between PASS and PB were not different (P > .05). Conclusions Transpulmonary cooling via cooled-air inhalation did not promote an optimal cooling rate (>0.15°C·min−1) for the successful treatment of EHS. In remote settings where EHS is a risk, access and use of treatment methods via CWI or cold-water dousing are imperative to ensuring survival. Trial Registry ClinicalTrials.gov (NCT0419026).

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