Environmentally Induced Hyperthermic Emergencies

 By Erik P. Steciak

This month’s article is going to look at heat related environmental emergencies. While there can be various causes or exacerbating factors, such as being outside in elevated temperatures or intense physical exercise without a respite or proper hydration, the end result is the same: the body can no longer thermoregulate itself correctly

Heat stroke, the most serious and potentially fatal form of environmental hyperthermia, is defined by the MMP as “Hot, dry skin (25% of patients will still be moist), seizures, altered mental status, dilated pupils, rapid heart rate, or arrhythmia.”

Now that that has been established, we shall look into several quick ways of diagnosing what level of hyperthermic emergency the patient is in. Skin color is a quick and easy way to assess your patient and rule in/rule out (RI/RO) heat stroke: if the skin is cool, the patient is in the cramp or exhaustion phase. The presence of moisture cannot be used to conclusively RI/RO heat stroke as 25% of all heat stroke patients will be moist. Assessing your patient’s mental status is also important: a patient in a environmentally induced hyperthermic emergency with an altered mental status should always be treated as a high priority patient until proven otherwise. Thus, heat stroke can be RI/RO in a matter of seconds simply by touching your patients skin and asking them a few questions.

Heat cramps generally only require passive cooling and rehydration. Heat exhaustion may be treated the same way, though some patients may benefit from more aggressive cooling by active means. Heat stroke must always be aggressively managed, with both passive and active cooling methods. Active cooling methods most commonly involve placing ice packs/cold to the neck, axilla, and femoral groin. While using cold compresses on the back of the neck may be effective, it is important to note that covering a patient in compresses is not ideal as they may act as insulation and help trap heat in.

ALS providers should gain IV access on all patients with heat stroke, as oral rehydration in a patient with an altered mental status is not recommended (and in some jurisdictions or states, such as Maryland, outright prohibited). If the local jurisdiction allows it, cooled IV fluids may be used to help lower the body’s core temperature in conjunction with other more standard methods. A heart monitor should be applied, and a 12/15 lead taken to rule out associated arrhythmias.

Assessing a patient experiencing an environmentally induced heat related emergency can be challenging, and should always be a thorough assessment in which the provider chooses to err on the side of caution. Brain damage and death can result from heat stroke, so when in doubt it is better to over-triage than under-triage these patients. Keep in mind various patient groups, such as the elderly, may not be able to thermoregulate as effectively as other patient groups. Finally, remember that ALS treatment and transport to a definitive care facility may be indicated if the patient’s condition does not improve after BLS treatments have been provided. Stay safe.


Erik P. Steciak has been involved in EMS since 2003, and is currently a Lead ALS provider for Special Events Medical Services.