Caregiver's Guide to the Difference Between Heat Stroke and Heat Stress for Seniors
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Caregiver's Guide to the Difference Between Heat Stroke and Heat Stress for Seniors

Summer's arrived in Evanston, Illinois, and that means heat and humidity. The combination can lead to a range of heat illnesses, beginning with heat rash and cramps and progressing to heat stress and stroke. Knowing the signs of heat illnesses can make a difference between positive and negative outcomes.

Excessive heat raises the body's core temperature which the body attempts to lower through sweat evaporation. When humidity is greater than 60%, it can be difficult for the body to dissipate excess heat. The body's quantity of salt and water becomes unbalanced, body temperature rises, and sweat does not cool the body. Heat rash and heat cramps can be treated by moving to a cooler space, drinking fluids, and resting. However, heat stress and stroke are more serious and can lead to a medical emergency. As temperatures rise and humidity increases, Chicago can feel like the tropics.

Heat Stress or Exhaustion

Heat stress isn't restricted to summer. When people remain in an excessively hot building or room with no air circulation, their body temperature can rise. Unless they remain hydrated and take cooling breaks, heat exhaustion may result.


If someone displays the following symptoms, they may be experiencing heat stress:

  • Rapid, shallow breathing
  • Muscle cramps
  • Headache
  • Elevated heart rate
  • Weak but elevated pulse
  • Pale skin
  • Nausea or vomiting
  • Dizziness or fainting

Unlike heat stroke, heat exhaustion does not affect one's mental status; however, anyone experiencing heat stress symptoms should contact a medical professional.


If someone exhibits heat stress symptoms, take them to a cool and shaded area or an air-conditioned room. The goal is to cool the body as quickly as possible. Once out of the heat, have the individual:

  • Sip cold water.
  • Put cold compresses on their skin.
  • Mist themselves with cool water.
  • Stand near a fan.

Call 911 or visit the emergency room within 30 minutes of feeling ill.


Recovery time from heat-related illnesses depends on the individual's age and the severity of the symptoms. For most people, recovery takes a few days once the body's core temperature returns to normal. 

Heat Stroke

According to the CDC, heat stroke is the most serious heat-related illness. With heat stroke, the body's core temperature can exceed 106°F in 10 to 15 minutes, making it impossible for the body to cool itself. Unless the individual's body temperature is lowered within 30 minutes of symptom onset, heat stroke can lead to permanent disability or death.


Heat stroke symptoms such as dizziness, fainting, and nausea resemble heat exhaustion; however, heat stroke impacts mental functions. Someone suffering from heat stroke may have difficulty speaking, be confused, or become agitated. Other symptoms include the following:

  • Hallucinations
  • Rapid, strong pulse
  • Dry, short skin
  • Temperatures in excess of  105 degrees F
  • Muscle spasms
  • Seizures

Call 911 or go to an emergency room immediately. The best outcomes occur when individuals receive medical attention within 30 minutes of symptom onset.


While waiting for emergency services, try the following to try to lower the person's body temperature:

  • Remove them to a cool location
  • Spray them with water
  • Apply cool compresses
  • Loosen or remove clothing
  • Do not let them drink fluids
  • Elevate their feet

Heat stroke is a serious medical condition that requires immediate attention.


Recovering from heat stroke depends on its severity and how quickly the individual receives medical attention.

Preventing Heat-Related Illnesses

The best way to treat heat-related illnesses is to prevent them from happening. Some health conditions and medications can increase the chances of heat exhaustion or heat stroke. Be sure to drink at least 16 ounces of water per hour in excessive heat. Avoid alcohol and caffeine. Eat light meals and stay in shaded or cooler areas.

For older adults in Cook County, having in-home care can help minimize the risk of heat-related illnesses. Senior Helpers® in Illinois provides in-home services ranging from specialized care to companion services for people 65 and older.