Heat Emergencies

Dr. Ashley Jacobson, MD

Summer heat making you feel more exhausted than normal? Or has COVID quarantine encouraged you to spend more time on mountain trails instead of staying indoors? Here are a few tips as we round out summer.

Heat illness is a spectrum of disease that ultimately culminates into heatstroke. Heatstroke separates into two different categories: Classic and Exertional. Classic heatstroke is predominately in elderly patients residing in poorly regulated temperature environments. Exertional heatstroke is predominately in athletes who overexert themselves during high temperature and humidity. Heatstroke presents as elevated core body temperature >40C and central nervous system dysfunction. The treatment for both is supportive cooling as soon as possible. First-line cooling measure involves ice water immersion. Third line treatment is evaporative cooling, which is typically utilized in medically complex or elderly patients for ease of monitoring; however, this also cools at a slower rate when compared to ice water immersion.

High altitude illness consists of High Altitude Pulmonary Edema (HAPE) and Acute Mountain Sickness (AMS), which can progress to High Altitude Cerebral Edema (HACE).

1. Do not ignore the signs and symptoms of high-altitude illness.
   1. HAPE: Dry to productive cough with dyspnea within four to six days of arrival
   1. AMS and HACE: Headache, nausea, vomiting, fatigue that progresses to ataxic gait, and encephalopathy within six hours to three days
2. Definitive treatment is descent. Can temporize with:
   1. HAPE: high-flow nasal cannula, rest
   1. AMS and HACE: antiemetics progressing to dexamethasone, acetazolamide, hyperbaric therapy
3. Prevention: gradual ascent
   1. HAPE: nifedipine, phosphodiesterase 5 inhibitors
   1. AMS and HACE: acetazolamide, dexamethasone

Two recent publications in ACEP Now by Dr. Ashley Jacobson and Dr. Neha Raukar discuss heat illness and high altitude illness. Access to these articles are here: https://www.acepnow.com/article/the-2020-icd-10-definitions-of-heat-illness-go-beyond-heatstroke/ and https://www.acepnow.com/article/tips-for-spotting-and-treating-high-altitude-illness/.