| Figure
s/Table
sFigure
s/Table
s | Reference
sReference
ssion=""1.0"" encoding=""UTF-8""?>
ss=""h4"">Objective
Heat illne
ss i
s a common ailment that, if left untreated, i
s a
ssociated with high morbidity and mortality. Chemical cold pack
s (CCP
s) and ice pack
s are widely u
sed in the pre-ho
spital
setting and by tho
se with limited re
source
s, yet no controlled
studie
s have compared the cooling of ice to that of CCP
s. Thi
s study determined the theoretical cooling of CCP
s on a benchtop model, comparing the re
sult
s to
similarly
sized ice pack
s, and i
s the fir
st known compari
son of the
se hyperthermia treatment
s.
ss=""h4"">Methods
The CCPs used in Stanford University's Emergency Department were activated in an insulated volume of water (2 L), and temperature was recorded at 1-second intervals in a controlled environment (41¡ãC at 20 % humidity). The procedure was repeated with 1-quart ice packs.
ss=""h4"">Results
The CCPs resulted in a 5.25¡ãC degree temperature drop, with a time constant (time to 63 % of initial temperature¡ªa common engineering characterization metric) of 1.72 minutes for the test volume. Ice packs resulted on average in a 19.8¡ãC temperature change, with a time constant of 26.8 minutes. The CCPs provide less overall temperature change and were shorter lived. Application of 6 CCPs on a 50th percentile male (weight 86.6 kg, height 1.7 m), assuming ideal heat transfer, would result in less than 0.5¡ãC temperature change. Similarly configured ice packs would result in a 2.5¡ãC change.
ss=""h4"">Conclusions
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.