Rationale:

• Heatstroke prognosis is thought to depend on the time period during which the rectal temperature is above a critical value (40°C [104°F]); therefore, the importance of rapid efficient cooling such as by immersion in ice water cannot be overemphasized.

Evidence:

• Hospital treatment for heatstroke should emphasize whole body cooling (4; 9; 20; 21; 22; 23).
• No evidence supports the superiority of any one cooling technique in patients with classic heatstroke (24).

Comments:

• Immediate initiation of cooling as soon as a diagnosis is reached is the cornerstone of treatment.
• Cooling by ice water can provoke shivering thermogenesis, thus lowering the cooling rate. Cardiac arrhythmias have also been provoked by ice water immersion. Therefore, in certain populations, such as elderly persons or patients with prior cardiovascular illness, use of ice water may be harmful (20; 25). Tepid water (26°C [78.8°F]) immersion may induce cooling at similar rates as ice water without coincident risk of complications (26). It is important to stop cooling when body core temperature reaches 38°C (100.4°F) to prevent over cooling (9).