AC out in a heat wave: how to stay safe
When the AC fails in extreme heat, protect people first: move vulnerable people to a cool place, drink water, and know the signs of heat stroke, which is a 911 emergency. Then try a few safe checks on the system. If it is still not cooling, call 833-877-1717 to request an independent AC repair provider.
RepairNowUSA editorial review · Last substantively reviewed October 13, 2026 · Review standards
People first: recognize heat illness
- Heat exhaustion: heavy sweating, cool clammy skin, weakness, dizziness, headache, nausea, muscle cramps. Move to a cooler place, loosen clothing, sip water, and cool down with damp cloths.
- Heat stroke: very high body temperature, hot skin (red, dry or damp), confusion, slurred speech, fainting or seizures. Call 911 and cool the person immediately while waiting.
Infants, young children, older adults, pregnant people, people with heart or lung conditions, and people on certain medications are at highest risk.
Safe checks to try
- Thermostat: set to "Cool", below room temperature, fresh batteries if needed.
- Breakers: AC usually has two: one for the indoor air handler or furnace, one for the outdoor unit. Reset a tripped breaker once only.
- Outdoor disconnect: a box on the wall near the outdoor unit. Make sure it was not pulled or switched off.
- Filter: a clogged filter can freeze the coil and choke airflow. Replace it.
- Ice: if you see ice on the refrigerant lines or indoor coil, turn cooling off and run the fan only for a few hours to thaw it. Running it frozen can damage the compressor.
- Condensate: a full drain pan or tripped float switch shuts the AC off. Water around the indoor unit is a clue.
- Outdoor unit: clear leaves, grass and debris from around it. Gently rinse the fins if they are matted with dirt.
If the outdoor unit hums but the fan does not spin, switch it off at the thermostat and call for service. Do not poke the fan or open the panel; capacitors inside hold a dangerous charge.
Cooling the home while you wait
- Close blinds and curtains on sunny windows.
- Avoid using the oven, dryer and other heat-producing appliances.
- Use fans to move air, but know that at very high temperatures fans alone may not prevent heat illness.
- Spend the hottest hours somewhere air-conditioned: a library, mall, cooling center, or the home of friends or family.
- Take cool showers and drink water regularly, even if you are not thirsty.
- Check on neighbors, especially older adults living alone.
- Portable or window AC units can cool one room as a stopgap.
Pets, medications and food
- Give pets water and shade, and never leave them in a hot car or closed hot room.
- Some medications and insulin must be kept below certain temperatures. Check the label or ask a pharmacist.
- Refrigerator performance drops in a very hot kitchen; keep the door closed.
What to tell the AC provider
- System type: central AC with a furnace, heat pump, ductless mini-split or packaged unit.
- What happens: nothing runs, the indoor fan runs but the outdoor unit does not, it runs but blows warm air, ice on lines, water leaking, breaker tripping.
- What you already checked.
- Whether anyone in the home is at higher risk from heat.
When you call 833-877-1717, RepairNowUSA looks for a participating independent AC provider in your area. The provider confirms timing and price with you. Availability can be tight during heat waves.
How RepairNowUSA can help
Call 833-877-1717 and describe what is happening and the property ZIP code. RepairNowUSA looks for a participating independent provider for that kind of work in your area and connects you if one is available. The provider confirms timing, scope and price with you and does the work. Availability and response times vary and are not guaranteed.
Call 833-877-1717Common questions
How hot is too hot inside a house?
There is no single safe number. Risk rises sharply for vulnerable people as indoor temperatures climb into the upper 80s and 90s, especially with high humidity. Do not wait for symptoms: move vulnerable people somewhere cool.
Can a fan keep me safe without AC?
Fans help with comfort, but in very high heat they may not prevent heat illness. Spending time in an air-conditioned place is more protective.
Why did my AC freeze up?
Common causes are a dirty filter, blocked return vents, low refrigerant from a leak, or a failing blower. Turn cooling off and run the fan to thaw, replace the filter, and call for service if it freezes again.
Is it worth adding refrigerant to my AC?
Refrigerant does not get used up. If it is low, there is a leak, and adding refrigerant without finding the leak is a temporary fix. Ask the technician about leak detection.
Can I call any time?
Yes. You can call 833-877-1717 at any time, including nights, weekends and holidays. Whether an independent provider can come out right away depends on your ZIP code, the time and provider capacity, so availability is not guaranteed.
Authoritative references
These public sources give general safety context. They do not replace an on-site evaluation, and RepairNowUSA does not perform the work.