The NYC Marathon is this Sunday! The city has been gifted with some unseasonably warm weather the past couple days, but this has the potential to cause problems for the thousands of runners. Today we will talk about heat exhaustion and stroke, which represents the most severe end of a spectrum of heat related illnesses.

Exertional heat related illnesses result because heat production and gain from the environment overwhelm the body’s removal processes and thus core temperature increases. Risk factors include strenuous exercise in high temperatures or humidity, lack of acclimatization to warm weather (usually takes 10-14 days), poor physical fitness, obesity and dehydration. The list of drugs that increase risk is long, but important to note is beta-blockers, antiepileptics, diuretics, lithium.

Symptoms of heat exhaustion include headache, nausea, vomiting, malaise, dizziness and muscle cramps. Temperature will be elevated, but <104F. Tachycardia and orthostatic hypotension can also result. Treatment is supportive and includes removal from environment, volume and electrolyte repletion and rest. If patients do not respond to after 30 minutes to fluid and removal from the environment, they should be aggressively cooled until the core temperatures is <102F.

Heat stroke is a life threatening emergency of altered mental status and temperature >104F. Patients can also exhibit ataxia and seizures. The goals of treatment are removal from the environment and cooling, along with standard resuscitation efforts including ABCs. Evaporative cooling is the method of choice, this is accomplished by removing patient’s clothes and spraying cool water over the body while fans blow over them. Temperature should be monitored and the goal is reduce to <102F and then stop methods to avoid overshooting. Antipyretics have no role in treatment. Seizures and shivering should be treated with benzos.