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A Miller Coulson Academy of Clinical Excellence Initiative

Advising Patients About Heat-Related Illness


Many heat-related illnesses are preventable. Advise patients to avoid going outdoors in peak heat hours, drink plenty of fluids, and know where cooling centers are in their community.

We were asked to see an 81-year-old frail woman who presented to the ED with confusion, hyperthermia, and dehydration. The patient was living independently and one afternoon when she decided to visit her daughter, she called for a cab and went outside, and then fell asleep on the staircase outside her house. There was a heat wave in Baltimore that week and the outside temperature was 98 degrees. A neighbor saw her and woke her up. She was weak and confused so he called EMS. In the ED her body temperature was 104 degrees and her skin was hot and dry. In the hospital she was treated for hyperthermia and confusion, but her cognition didn’t return completely to baseline.


Over the last few decades global warming has caused unusually high summer temperatures, which are becoming common throughout the U.S. and around the world. As of June 2021, 1,380 heat-related illness ED visits were reported by the CDC. Approximately 700 adults die each year from the direct consequences of a heat-related illness. These numbers are higher than any other weather-related deaths in the U.S.. Excessive heat can disrupt thermoregulation and result in a variety of clinical syndromes ranging from mild heat edema, dyspnea, and tachycardia, to muscle cramps and more severe conditions including heat exhaustion and heat stroke, which are medical emergencies. High temperature can also lead to heart attacks, strokes, and other forms of cardiovascular problems. Exertional heat-related illness is more common in athletes, laborers, and military personnel, while non-exertional heat related illness is seen more commonly in older adults, young children, and people who are homeless. Co-morbid conditions such as renal disease, dementia, and the use of certain medications such as beta blockers, calcium channel blockers, antipsychotics, and diuretics further increase risk. During a heat wave some patients without air conditioning or in bedrest with limited access to water may suffer from heat related illnesses without going outside. Healthcare professionals should have high clinical suspicion, as most of these patients present with vague symptoms from dizziness, nausea, and fatigue, to confusion and coma.


Our patient’s kidney function improved with prompt rehydration and her temperature came down with the use of cooling blankets, but her cognitive status didn’t return to baseline. She was discharged with home care, and her family arranged for daily visits to ensure that she was safe and drinking two liters or more every day.


Heat-related illness is preventable by simple measures during a heat wave. You can advise patients to:


1. Avoid going outdoors in peak heat hours, which are from 10 a.m. to 3 p.m..

2. Drink plenty of fluids, at least two liters per day. Know where free water sources are located.

3. Make sure there is adequate air conditioning during heat waves. Know where cooling centers are located.

4. Clinicians should check for medications that increase the risk for heat-related illness.

5.  If you have to go outside during the hottest times of day,  wear sunscreen and loose, light-colored clothes to help avoid heat accumulation.


To learn more: Tips for Preventing Heat-Related Illness | Natural Disasters and Severe Weather | CDC






This piece expresses the views solely of the author. It does not represent the views of any organization, including Johns Hopkins Medicine.