AC out during a heat wave

Quick answer

If anyone shows signs of heat stroke, such as confusion, a very high body temperature or fainting, call 911 right away. Otherwise, get vulnerable people to an air-conditioned place, block the sun and drink fluids, then check the thermostat and filter while you arrange an HVAC repair.

Safety first: Heat stroke is a medical emergency: call 911 or get the person to a hospital immediately. Fans can make you feel cooler but do not lower body temperature or prevent heat-related illness.

What to do now

  1. Know the signs of heat illness. Heat stroke signs include a throbbing headache, confusion, slurred speech, body temperature above 103 degrees F, hot red skin, and loss of consciousness. Call 911 right away; delay can be fatal. Source: Heat Cramps, Exhaustion, Stroke - National Weather Service
  2. Get to a cool place. If air conditioning is not available at home, find a cooling center or another cool public place such as a library or shopping mall. Source: Extreme Heat - Ready.gov
  3. Do not rely on fans alone. Fans create air flow and a false sense of comfort, but they do not reduce body temperature or prevent heat-related illness. Source: Extreme Heat - Ready.gov
  4. Keep the heat out. Cover windows with drapes or shades, wear loose, lightweight, light-colored clothing, drink plenty of fluids, and avoid high-energy activity during the hottest part of the day. Source: Extreme Heat - Ready.gov
  5. Check on people at higher risk. Young children, older adults and people with chronic conditions are more vulnerable, especially without air conditioning. Never leave a child, disabled person or pet in a parked car. Source: Heat Safety Tips and Resources - National Weather Service
  6. Check the thermostat and filter. Confirm the thermostat settings are correct and look at the air filter; a dirty filter can damage the equipment. A clogged condensate drain can also affect how the system runs. Source: Maintenance Checklist - ENERGY STAR

When to call a professional

Call an HVAC company for air conditioner or heat pump repair. Tell them if anyone in the home is elderly, very young or medically vulnerable, describe what the system is doing, and ask how soon they can come and whether they check refrigerant, electrical parts and the drain line.

Find HVAC companies (427 listed)

Pick your state and city on the directory page, or use the location search at the top of this page, then call a local company directly.

Frequently asked questions

Is a fan enough to stay safe?

No. Ready.gov notes that fans create a false sense of comfort and do not reduce body temperature or prevent heat-related illness. Go to a cooling center or other air-conditioned place if you can.

What are the signs of heat stroke?

The National Weather Service lists confusion, slurred speech, a throbbing headache, body temperature above 103 degrees F, hot red skin, a rapid strong pulse, fainting and loss of consciousness. Call 911 immediately.

What can I check myself before calling?

Check the thermostat settings and the air filter. Electrical and refrigerant problems should be left to a technician.

General safety information, not professional advice. In an emergency, call 911. More guides: home emergencies: what to do first.