From the Guidelines
The most appropriate treatment for this 72-year-old man with heat stroke is evaporative cooling (option C). This patient presents with classic signs of heat stroke including hyperthermia (temperature 40.5°C/104.9°F), altered mental status (somnolence), warm and dry skin, tachycardia, and hypotension after exposure to high environmental temperatures. Evaporative cooling involves spraying the patient with tepid water while directing fans to blow air across the body, which promotes heat loss through evaporation. This method is effective, readily available in most emergency departments, and less likely to cause complications compared to ice water immersion, which can cause peripheral vasoconstriction and shivering that may paradoxically increase core temperature. According to the 2024 American Heart Association and American Red Cross guidelines for first aid 1, for adults with heatstroke, it is reasonable to initiate immediate active cooling by using whole-body cool- to cold-water immersion or other forms of active cooling, including evaporative cooling. Acetaminophen would not be effective for environmentally-induced hyperthermia as it targets the hypothalamic set point, which is not the issue in heat stroke. Dantrolene is indicated for malignant hyperthermia associated with certain anesthetics, not environmental heat stroke. Rapid cooling is essential in this case as heat stroke has a high mortality rate if not promptly treated, with the goal being to reduce core temperature to below 39°C as quickly as possible. Some studies suggest that full-body ice water immersion can be an effective treatment for exertional heatstroke 1, but evaporative cooling is a more practical and readily available option in most emergency departments. Additionally, the management of circulatory failure in heatstroke is also important, and fluid replacement sufficient to restore blood pressure and tissue perfusion is recommended 1. However, the most recent and highest quality study 1 supports the use of evaporative cooling as a reasonable and effective treatment for heat stroke.
Some key points to consider in the treatment of heat stroke include:
- Rapid cooling to reduce core temperature to below 39°C as quickly as possible
- Evaporative cooling as a practical and effective treatment option
- Fluid replacement to restore blood pressure and tissue perfusion
- Avoidance of acetaminophen and dantrolene in the treatment of environmental heat stroke
- Consideration of the patient's overall clinical condition and medical history in determining the best course of treatment.
From the Research
Treatment Options for Heat Stroke
The patient's symptoms, including a body temperature of 40.5 °C (104.9 °F), somnolence, and flushed, warm, and dry skin, are consistent with heat stroke. The most appropriate treatment for heat stroke is rapid cooling to lower the body's core temperature.
Cooling Methods
- Evaporative cooling: This method is a rapid and effective alternative to immersion in an ice-water bath 2.
- Immersion in ice water: This is the most effective cooling method, but it may not be feasible in all settings 2, 3, 4.
- Other methods, such as ice pack application and convective cooling, may also be used, but they are generally less effective than evaporative cooling or immersion in ice water 5, 4.
Medications
- Dantrolene: This medication has been used to treat malignant hyperthermia and neuroleptic malignant syndrome, which have similarities to heat stroke 6. However, its use in heat stroke is not well established.
- Acetaminophen: This medication is not recommended for the treatment of heat stroke, as it does not effectively lower the body's core temperature.
Recommended Treatment
Based on the available evidence, the most appropriate treatment for this patient is evaporative cooling (option C) or immersion in ice water (option D). However, since option C is a more feasible and readily available method in most settings, it is the recommended choice.