Heat Exhaustion vs. Heat Stroke

Summer in Iowa. It could be 75, it could be 105. One thing is for sure though. If it's the latter, it doesn't take long to be stricken with a heat-related illness. Especially for those who have to work outside, or don't have air conditioning.

Heat-related illnesses can occur suddenly, so it’s fairly common for people suffering from them to be seen in the Emergency Department. Here, Steve Gelder, Mary Greeley's Director of Emergency Services, and Beth Frandsen, Director for Mary Greeley's Mobile Intensive Care Services discuss the difference between heat exhaustion and heat stroke, when to seek medical attention and how both are treated.

Q: We’ve all heard about heat exhaustion and heat stroke–can you talk about the difference between the two?

Heat exhaustion develops when a person is working or exercising in hot weather and does not drink enough to replace lost liquids.

Heat stroke occurs when the body fails to regulate its own body temperature and the body temperature continues to rise. Heat stroke is a true medical emergency and requires immediate cooling and fluid replacement.

Q: Sometimes when you come in from outside during the summer you’re sweaty and may feel tired or weak, but sometimes that’s just from having been outside and isn’t necessarily heat exhaustion or heat stroke–at what point should someone seek medical attention?
Signs and symptoms of heat-related illness may include:

• an elevated body temperature
• headache
• nausea
• dizziness
• fainting
• muscle cramps
• seizures
• confusion
• coma

Symptoms may present in mild degrees, but if the condition becomes more severe or worsens with time, contact a physician. It’s also important to note that many medications increase an individual’s risk to heat-related illness, and that infants, older individuals, obese individuals and those with chronic medical conditions are more susceptible to heat-related illnesses.

Q: Besides staying hydrated while outside, what other precautions can people take to protect themselves?

• Wear appropriate clothing and use sunscreen.
• Remain in a cool environment if possible, or limit one’s exposure when temperature and humidity are high.
• Keep the body cool and avoid dehydration. Even loosening clothing and a fan will provide some relief.
• Ice packs to the neck, armpits and groin can help to rapidly cool an individual when heat-related symptoms appear.

Q: Once someone has made it to the Emergency Department–how are the two (heat exhaustion and heat stroke) treated?

Both are treated primarily with fluid replacement. With heat exhaustion, fluids (by mouth or IV) and rest are typically all that is needed. Heat stroke requires a bit more work. The goal is to lower the patient’s body temperature and that is done with cooled IV fluids as well as cool packs in areas such as the armpits and groin. Lab tests will be ordered, an EKG will be performed to check for any cardiac abnormalities, and most likely you will be admitted for observation until your condition improves.