Heat waves are a period of unusually hot weather usually lasting 2 or more days. In Colorado, that means multiple days with temperatures above 90 degrees. 

Extreme heat can cause heat-related illnesses (HRI) which may take many forms ranging from fatigue to muscle cramping, to heat stroke. Heat waves are becoming increasingly common,  so it’s important to stay cool, stay informed, and take precautions to avoid heat-related illnesses. 

Fast Facts about Heat Safety 

  • Extreme heat can be dangerous. Heat waves can cause heat-related illness (HRI), such as heat stroke or heat exhaustion. 
  • Prevent heat-related illness by drinking water often, staying in a cool place with air conditioning, and wearing loose-fitting, light-weight clothing. 
  • Extreme heat causes the highest number of deaths each year out of all weather-related disasters such as flood, lightning, or tornados.  
  • Older adults, children and sick or overweight individuals are at greater risk from extreme heat. Use a buddy system and regularly check-in with people who are higher risk twice a day during a heat wave. 
  • Pets can also suffer from extreme heat. Make sure pets have cold water and plenty of shade and never leave pets in a parked car.

Extreme heat without relief can cause heat-related illness (HRI). There are several types of heat related illness:

  • Heat cramps: This is the mildest form of heat illness. Heat cramps are painful muscle cramps or spasms that happen during or after exercise or sweating in high heat. 
  • Heat Exhaustion: This is a more serious form of heat related illness that is caused by loss of water and salt in the body. This can happen when you sweat without replacing enough fluids and salt. When you have heat exhaustion, your body is not able to cool itself properly and if not treated, this can lead to heat stroke. 
  • Heat Stroke: This is the most severe form of heat illness and happens when the body’s temperature regulating system is overwhelmed with too much heat. This is life-threatening and requires immediate medical attention. 

Heat-related illness is preventable! Learn how to spot heat-related illness and get medical care immediately if you or someone you know are showing signs.  

Heat-Related Illness Signs and What to Look For First-Aid and Treatment
Heat Stroke
  • High body temperature
  • Hot, red, dry, or damp skin
  • Fast, strong pulse
  • Headache
  • Dizziness
  • Nausea
  • Confusion
  • Losing consciousness (fainting or passing out)
  • Call 911 and seek medical care immediately. Heat stroke is a medical emergency. 
  • Move the person to a cooler place
  • Do not give the person anything to drink
  • Help lower the person's body temperature using cool, damp cloths or a cool bath. Fan their damp skin. 
  • Place ice bags on the armpits and groin areas
Heat Exhaustion
  • Heavy sweating
  • Cold, pale, or "clammy" skin
  • Fast, weak pulse
  • Nausea or vomiting
  • Muscle cramps
  • Tiredness or weakness
  • Dizziness
  • Headache
  • Fainting (passing out)
  • Move to a cool place and rest
  • Loosen clothing 
  • Put cool, damp cloths on your body or take a cool bath
  • Drink cool sports drinks that have salt and sugar
  • Get medical help right away if: There is no improvement or you are unable to take fluids


Heat Cramps
  • Heavy sweating during intense exercise
  • Muscle pain or spasms
  • Stop participating in physical activity
  • Move to a cool area 
  • Wait for cramps to go away before you start more physical activity
  • Drink cool fluids or sports drinks containing salt and sugar
  • Stretch any cramped or spasming muscles gently and slowly
  • Get medical help right away if: your cramps last longer than 1 hour, you're on a low-sodium diet, or you have heart problems. 
Heat Rash
  • Red clusters of small blisters that look like pimples on the skin (usually on the chest, neck, groin, or elbow creases)
  • Stay in a cool, dry place
  • Keep the rash dry



Anyone can be affected by heat related illness and proper prevention is important for everyone during a heat wave. 

Some groups are at higher risk for heat related illness, including:

  • Infants and children up to 4 years of age
  • People 65 years of age and older
  • People who are pregnant
  • People with some chronic medical conditions
  • Athletes
  • Outdoor Workers 
  • People experiencing homelessness

We can all do our part to keep our communities safe from heat related illness.  If you are 65 years of age or older, have a friend or relative call to check on you twice a day during a heat wave. If you know anyone in this age group, check on them at least twice a day. When working or playing sports in the heat, check-in with coworkers and teammates and have someone do the same for you. 

  • Whenever possible, spend time in an air-conditioned area.  If your home does not have air conditioning, go to a shopping mall, library or other place that does. Even a few hours in an air conditioned environment can keep the body cool.
  • Drink plenty of water often, don’t wait until you are thirsty to drink. 
    • Avoid drinks with large amounts of sugar and alcohol, as they can cause a loss of fluid. 
  • Provide pets with plenty of fresh water.
  • Avoid preparing or eating hot meals. This can heat up your living space and add to body heat.
  • Limit outdoor activities to when it’s coolest (usually early morning)
    • If you must be outdoors, take regular breaks in the shade. 
  • Wear clothes that are lightweight, light-colored, and loose-fitting
  • Visit adults who are at greater risk at least twice daily, and watch them closely for signs of heat exhaustion or heat stroke.
  • Be safe on the job. If your job involves physical work outdoors:
    • Drink water every 15 minutes, even if you do not feel thirsty.
    • Wear a hat and light-colored clothing.
    • Rest in the shade
    • Wear sunscreen of SPF 15 or higher and reapply every 2 hours, especially when sweating.