By Sara McCloskey-Nieves 

There are two words no one wants to hear in the forecast before a holiday weekend: extreme heat.  

But that weather is exactly what’s in store for millions in the United States ahead the Fourth of July holiday.

Thousands of people go to the hospital every year because of illnesses brought on by the heat. While there are many precautions we can take to try to stay cool and hydrated, sometimes they’re not enough to prevent heat-related illnesses.

“Heat-related illness can affect anyone, not just older adults. Even young, healthy individuals can become seriously ill if they overdo it in the heat,” said Michael Vitto, DO, chief of the Department of Emergency Medicine at VCU Medical Center. “Alcohol consumption is a major factor; it contributes to dehydration, impairs judgment and can make people less aware of the early warning signs of heat illness.”

One of the most common conditions that emergency departments — like the one at VCU Medical Center — treat during hot weather is heat exhaustion, which happens when the body is overheating and losing significant water and salt, typically from excessive sweating.

In a matter of minutes, however, heat exhaustion could become its deadly cousin, heat stroke. If the body cannot cool itself down, the body’s core temperature will rapidly rise, becoming a medical emergency.

Extreme heat puts everyone at risk. Knowing the difference between these two illnesses can save lives. VCU Health News spoke with Vitto to identify three symptoms to closely monitor if someone begins to show signs of a heat-related illness.

Core body temperature rises quickly with heat stroke

Heat exhaustion causes heavy sweating, which means the body can still regulate itself.

But this can change quickly. Once body temperature skyrockets to 103 degrees or higher, you are in heat stroke territory.

Sweat — or lack thereof — can make skin appear different depending on the illness

Since the body is still producing sweat, skin tends to be cool and clammy with heat exhaustion.

On the other hand, the body may stop sweating with heat stroke, making skin red, hot and dry. Heat stroke can also cause profuse sweating.

Dizzy vs. Disoriented: Mental state changes with heat-related illnesses 

One of the biggest red flags that someone may be experiencing heat stroke — and a true medical emergency — is a change in their mental state, Vitto says.

While people may feel dizzy with heat exhaustion, they are coherent and act normally.

Heat stroke is the opposite: People may feel confused, agitated or disoriented. Their speech may slur and, in severe cases, they could lose consciousness, experience a seizure or go into a coma.

“Heat exhaustion typically causes heavy sweating, dizziness, nausea, weakness and muscle cramps, but heat stroke occurs when the body's temperature regulation fails and vital organs — especially the brain — begin to be affected,” Vitto said.

When to call 911 for a heat-related illness 

Heat exhaustion can be treated at home, but go to urgent care if symptoms (mild to moderate) are not getting better.

Heat stroke is a medical emergency — call 911 or go to an emergency department.

“While waiting for EMS, begin cooling the person right away. The sooner we can lower the body's core temperature, the better the outcome,” Vitto said. “Delaying treatment increases the risk of permanent damage to the brain, kidneys, liver and heart, and in severe cases, heat stroke can be fatal. Early recognition and rapid cooling truly save lives.”

How to prevent your body from overheating

There are many things you can do to beat the heat when at home or outdoors. Vitto recommends being proactive rather than reactive and never ignore the warning signs of heat-related illnesses. 

“Don't wait until you feel overheated,” he said. “Taking a short break to cool off is much easier than recovering from a trip to the emergency department.”

Here are more tips to keep you cool and safe in warm weather:

• Stay hydrated: Regulate your body temperature by drinking plenty of fluids. Even mild dehydration can affect you mentally and physically.
• Schedule activities carefully: On days when the heat index is 100 degrees or higher, health experts recommend limiting outdoor activities and staying in air conditioning instead.
• Find shade: Use a tree, umbrella or other cool shelter to keep your body from overheating. For the most protection, wear a hat and sunglasses.
• Use sunscreen: Sunburn affects your body's ability to cool down. Use broad-spectrum sunscreen with an SPF of 15 or higher. Reapply throughout the day, especially after swimming, sweating or drying off with a towel.
• Stay cool indoors: On days when it's too hot to go outside, stay inside with the air conditioning. If your home does not have AC, try to find a public area or local cooling shelter to spend some time. Electric fans will not prevent heat-related illnesses when the temperature is in the upper 90s, but you can cool down in other ways: take a cool shower or bath and limit how much you use your stove and oven.

If you start to feel sick, find a place to cool down and drink fluids. Discover more tips to prevent heat-related illnesses from VCU Health experts.

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