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Safety & emergency preparedness

Heat-related illness

Very hot weather can make it harder for you to cool down.

Muscle cramps may be the first sign of heat-related illness.

Symptoms include: heavy sweating and painful muscle spasms –often in the abdomen, arms, or calves.

What to do:

  • Stop activity and move to a cooler location
  • Drink water
  • Seek medical attention if cramps persist for more than one hour

Heat exhaustion can develop after several days of exposure to high temperatures and inadequate replacement of fluids. Those most prone to heat exhaustion are elderly people, people with high blood pressure, and people working or exercising in a hot environment.

Symptoms include: heavy sweating, headache, weakness, fatigue, dizziness, fainting, nausea or vomiting.

What to do:

  • Go to an air-conditioned space. On especially hot days the City opens cooling centers. 
  • Sip cool, non-alcoholic beverages
  • Take a cool shower or bath
  • Rest
  • Seek medical attention if symptoms persist for more than one hour

Heat stroke is the most serious heat-related illness. Heat stroke can cause death or permanent disability if emergency treatment is not provided.

Symptoms may include: very high body temperature (above 103°F), red, hot, dry skin (no sweating), confusion, throbbing headache, nausea, and unconsciousness.

If you see someone with these symptoms, call 911 immediately—this is a medical emergency.

At risk:

  • People aged 65 years or older. They are less likely to sense and respond to changes in temperature. Many people, particularly older adults, also don’t feel thirsty until they’re already dehydrated. You should check in on older adults to make sure that they are staying cool and hydrated.
  • Infants and young children (under age 4). Young children are sensitive to the effects of excessive heat and must rely on their caregivers to stay cool and hydrated.
  • People with some chronic medical conditions, like diabetes, cardiovascular disease, and asthma. They are less likely to sense and respond to changes in temperature. Also, they may be taking medications that can contribute to dehydration or interfere with the body’s ability to regulate body temperature. Patients should check with their healthcare provider for more information about how specific chronic conditions and medications may affect them during extreme heat events.

Even people without chronic conditions can be at risk during hot weather. People who are homeless, pregnant, work outdoors, or are athletes should be especially careful to stay hydrated.

Chronic medical conditions

  • DiabetesPeople with diabetes get dehydrated more quickly. High temperatures can change how your body uses insulin. People with diabetes may need to test their blood sugar more often and adjust their insulin dose and what they eat and drink.
  • Cardiovascular disease — People with heart disease may be more vulnerable to heat stroke. Some medicines commonly used to treat high blood pressure, like diuretics (water pills), can worsen dehydration.
  • Respiratory diseases, (asthma) — High temperatures can also impact air quality and worsen respiratory conditions, like asthma. Visit AirNow to check air quality ratings each day and plan your activities accordingly.