Chemical Cold Packs May Provide Insufficient Enthalpy Change for Treatment of Hyperthermia

Abstract

Experiments demonstrate that CCPs are inferior to similarly sized ice packs for thermal regulation, and lose their effectiveness more quickly. These findings support the consideration of ice packs as an alternative to chemical cold packs when cooling hyperthermic patients.

Exertional heat illness in Thoroughbred racehorses – Pathophysiology, case definition and treatment rationale

“…Two pouches filled with crushed ice are positioned, one on either side of the upper part of the neck, over the jugular vein and carotid artery, creating a 'heat sink' effect in the contacting tissues (Figs 13 and 14). Although the pouches can accommodate commercially available chemical cold packs, research has shown that crushed ice has a greater cooling capacity and remains colder for longer, maximising the 'heat sink' effect (McMeekan et al 1984;Phan et al 2013).…”

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2019 Update

“…98 Limited studies show no benefit in heat reduction with ice packs or chemical cold packs applied to these areas. 99,100 Ice packs have been found to have greater cooling capacity than chemical cold packs, 101 and if used, are most efficacious when wet and covering the entire body (to optimize conductive cooling). 99 A small translational study applied chemical cold packs to the glabrous skin of the palms, soles, and cheeks and found twice the cooling rate over traditional major vascular locations, 102 using the high-capacity blood flow of the subcutaneous arteriovenous anastomoses.…”

Novel Application of Chemical Cold Packs for Treatment of Exercise-Induced Hyperthermia: A Randomized Controlled Trial

“…To avoid this, the temperature of the skin must remain above the temperature threshold for local vasoconstriction. The CCP of this study uses an endothermic reaction to reduce temperature and cool to approximately 13°C, 24 a temperature that is not associated with vasoconstriction, especially in the glabrous skin regions. Colder temperatures (as induced by ice packs) increase the likelihood of experiencing a vasomotor response and subsequently decreasing their local cooling effects.…”

“…The CCP were agitated, applied, and then replaced every 9 minutes, corresponding to their average cold lifespan. 24 No water was consumed during the trials, but after each trial each participant consumed the volume of water equivalent to the weight lost during the trial.…”

“…24 No water was consumed during the trials, but after each trial each participant consumed the volume of water equivalent to the weight lost during the trial. The participants were subjected to three trials, each with a minimum of 24 hours between trials to allow for full recovery: 1) no treatment (control); 2) traditional treatment (one CCP applied to bilateral neck, axillae, and groin; six in total); or 3) glabrous treatment (one CCP applied to bilateral cheeks under the balaclava, palms [inside the gloves], and soles of the feet [inside of insulating boot covers]; six in total).…”