Immersion in an ice water bath is a common method of cooling heatstroke patients. Place the patient in a tub of ice water for 10 to 40 minutes (Figure 190-2). Briskly massage the patient's extremities to maintain peripheral circulation and promote heat loss. Monitor the patient's core temperature carefully. Rectal temperatures will decrease approximately 0.16 to 0.21°C/min.8,11
Ice water immersion is recommended by some authors as the initial technique for hyperthermia management.6,13,14 Unfortunately, it has limited use in the Emergency Department.4,11 Preparing an ice bath can result in a delay in cooling the patient. Contact with the ice water results in intense vasoconstriction, which blocks heat exchange, paradoxically increases core body temperature, induces shivering, and is uncomfortable for the patient. Heat transfer from the core to the surface is reduced. The practical issues of impairing access to the patient, monitoring the airway, and initiating resuscitative measures are challenging when the patient is in an ice water bath.4,11,15 The tub and patient lift device are large, bulky, and not often available in the Emergency Department. Multiple caregivers are required to prevent the patient from drowning and to maintain their head above water.
A simpler and easier method is immersion of just the patient's hands and forearms.16 This method requires less patient cooperation than full body immersion. It also allows for full patient monitoring during the cooling process.