Apartment Emergency · Stay
Staying cool without AC.
Heat kills more Americans than any other weather hazard in most years. In an apartment without air conditioning, the building itself can become dangerous. Here is how to cool down, when a fan stops helping, and when to leave.
The problem
Apartments trap heat by design.
The same thermal mass that helps apartments stay warm in winter works against you in summer. Concrete, brick, and asphalt absorb heat during the day and release it slowly at night. In dense urban areas, this heat island effect means outdoor temperatures can be 10 to 20 degrees warmer than surrounding rural areas, and the building never fully cools overnight.
Top-floor apartments bear the worst of it. The roof absorbs direct sun all day, and heat radiates downward into the unit below. A top-floor apartment with no AC can exceed 100 degrees Fahrenheit within a few hours during a summer heat wave. Interior and lower-floor units are better insulated by surrounding apartments, but they still accumulate heat over a multi-day event.
Unlike winter cold, summer heat does not give you as much time. Hypothermia develops over hours. Heat stroke can develop in minutes. Your decision window is shorter, and the consequences of waiting too long are more severe.
Two scenarios, different problems
Power outage (no electricity at all)
No AC, no fans (unless battery-powered), no refrigerator. The apartment heats up and stays hot. Your only tools are passive cooling, body-wetting, and battery fans. This is the more dangerous scenario.
AC failure (power is on, HVAC is broken)
You still have electricity for fans, can run a portable AC unit if you have one, can keep the refrigerator running for cold water and ice. Less dangerous, but still uncomfortable and potentially hazardous during extreme heat if the landlord does not fix it quickly.
What works
Cool your body, not the room.
Without AC, you cannot meaningfully lower the air temperature in your apartment. Instead, focus on lowering your body temperature. Water on skin is the most effective tool you have. Everything below works without electricity.
Wet your skin
Evaporation is how your body cools itself. Help it along. A cool shower or bath is the fastest way to drop your core temperature. If water pressure is gone, a damp towel on the back of your neck, wrists, and forehead works. A spray bottle of water misted on skin provides continuous evaporative cooling.
A wet sheet hung in a doorway with a battery fan behind it creates a crude but effective swamp cooler. The fan blows air through the wet fabric, lowering the air temperature by several degrees. This works best in dry climates; in high humidity, evaporation slows and the effect is reduced.
Cross-ventilate after dark
During the day, keep windows and blinds closed to block solar gain. After sunset, when outdoor temperatures drop below indoor temperatures, open windows on opposite sides of the apartment to create a cross-breeze. Place a battery fan in one window facing outward to pull hot air out; the opposite window draws cooler air in.
This is the most effective free cooling strategy for nighttime. It works poorly in heat waves where overnight temperatures stay above 80 degrees, but in most summer outages it provides meaningful relief between about 9 PM and 8 AM.
Hydrate aggressively
Drink water before you feel thirsty. Thirst is a late signal; by the time you feel it, you are already mildly dehydrated. The CDC recommends drinking water regularly during hot weather and not waiting until you are thirsty.
Avoid alcohol and caffeine, which accelerate dehydration. If you are sweating heavily, add a pinch of salt to your water or drink an electrolyte solution. Your refrigerator (if it still has power) or your stored water supply should be your first resource. Fill bottles and containers from the tap before you lose water pressure.
Sleep low and light
Hot air rises. If you have a multi-level unit, sleep on the lowest floor. If not, sleep on the floor rather than the bed. A damp sheet as your only cover provides evaporative cooling while you sleep. Set a phone alarm to check on yourself and drink water during the night.
Wear minimal, loose-fitting, light-colored clothing made from cotton or moisture-wicking fabric. Dark and tight clothing traps heat against your skin.
Battery fans
When fans help. When they do not.
A fan does not cool the air. It moves air across your skin, which accelerates sweat evaporation. That evaporation is what cools you. This works when the air temperature is below your body temperature (roughly 95 to 98 degrees Fahrenheit). Above that, a fan blowing hot air on your body can actually make things worse by accelerating heat transfer from the air into your skin.
The fan decision
Below
95°F
Fan helps.
Air movement accelerates sweat evaporation. A battery-powered fan running at 5 to 15 watts is one of the best uses of your power station or power bank capacity. A USB-rechargeable fan ($15-$30) can run 8 to 20 hours on its own battery.
Above
95°F
Fan only helps with wet skin.
At air temperatures above body temperature, a fan without skin wetting can increase heat stress. Combine the fan with a misting spray bottle, a damp towel draped over your shoulders, or a wet bandana. The National Weather Service notes that fans can make you hotter at heat index values in the high 90s and above.
Source: NWS, "What to do for Heat Cramps, Exhaustion, Stroke," weather.gov.
Recognize the danger
Heat illness is a progression.
Heat cramps lead to heat exhaustion, which leads to heat stroke. Each stage is more dangerous than the last. Heat stroke is a medical emergency that can cause permanent disability or death. Recognizing the earlier stages is how you prevent reaching the later ones.
Heat cramps
Signs: Painful muscle cramps and spasms, usually in legs and abdomen. Heavy sweating.
What to do: Stop activity. Move to a cooler spot. Massage the cramping muscles. Sip water. If cramps last longer than an hour, seek medical attention.
Heat exhaustion
Signs: Heavy sweating, weakness or tiredness, cool and clammy skin, fast weak pulse, muscle cramps, dizziness, nausea or vomiting, headache, fainting.
What to do: Move to a cooler environment. Loosen clothing. Apply cool, wet cloths or take a cool bath. Sip water. If symptoms worsen or last longer than one hour, or if the person vomits, seek medical attention immediately.
Heat stroke
Medical emergencySigns: Body temperature above 103 degrees Fahrenheit. Throbbing headache. Confusion, slurred speech, or altered mental state. Hot, red skin that may be dry or damp. Rapid, strong pulse. Fainting or loss of consciousness. The person may stop sweating despite the heat.
What to do: Call 911 immediately. Heat stroke is a severe medical emergency. Delay can be fatal. Move the person to a cooler environment. Cool the body as quickly as possible using cool cloths, a bath, or any water available. Do not give fluids if the person is unconscious.
Why it matters: According to the CDC, heat stroke can cause body temperature to rise to 106 degrees Fahrenheit or higher within 10 to 15 minutes. It can cause permanent disability or death without emergency treatment. Heat stroke impairs brain function before the person experiencing it recognizes what is happening. If someone is confused, agitated, or speaking strangely on a hot day, treat it as heat stroke until proven otherwise.
Source: CDC/NIOSH, "Heat-related Illnesses," cdc.gov, March 2026. NWS, "What to do for Heat Cramps, Exhaustion, Stroke," weather.gov.
Who is most at risk
Heat affects some people faster than others.
The CDC identifies several populations at higher risk during extreme heat. If anyone in your household falls into these categories, your decision to leave should come sooner and your monitoring should be more frequent.
Older adults (65+)
Aging reduces the body's ability to regulate temperature, produce sweat, and sense heat. Many medications taken by older adults (blood pressure medications, diuretics, antidepressants, antihistamines) further impair heat regulation. Older adults may not feel thirsty when dehydrated. Check on them frequently and offer water proactively.
Infants and young children
Children heat up 3 to 5 times faster than adults. They rely entirely on caregivers to keep them cool and hydrated. Dress them in minimal clothing, keep them in the coolest room, and monitor their skin color and alertness. Flushed skin, irritability, and lethargy are early warning signs.
People with chronic conditions
Heart disease, lung disease, kidney disease, diabetes, and obesity all increase heat vulnerability. People with mental health conditions may have impaired awareness of heat danger. Multiple medications can compound the effect. If anyone in the household has chronic conditions and the apartment is hot, leave early.
The decision
Leave before you feel sick. Not after.
Heat illness impairs your judgment before it impairs your body. By the time you feel confused or disoriented, you may not be capable of making good decisions about leaving. The time to leave is when you notice the apartment is getting hotter and you have no effective way to cool it, not when you start feeling symptoms.
Healthy adults: indoor temp above 95 degrees with no effective cooling
If your apartment has reached 95 degrees, you cannot cross-ventilate effectively, and you do not have a battery fan with misting capability, it is time to go to a cooled space. Staying "because the power might come back soon" is a gamble that gets riskier by the hour.
Vulnerable populations: indoor temp above 85 degrees for more than a few hours
For older adults, infants, and people with chronic conditions or heat-sensitive medications, a lower threshold is appropriate. Harvard researchers have documented health impacts in older adults at ambient temperatures as low as 85 degrees Fahrenheit. If the apartment is above 85 degrees and trending upward with no relief in sight, relocate.
Anyone showing heat illness symptoms: immediately
Dizziness, nausea, headache, rapid pulse, confusion, or cessation of sweating. Move the person to a cool environment and begin cooling immediately. If symptoms suggest heat stroke (confusion, very hot skin, loss of consciousness), call 911. Do not wait to see if it improves.
Where to go
- A cooling center. Many cities open cooling centers during heat emergencies. Libraries, community centers, and senior centers often serve this role. Your city or county emergency management website will list locations. Some operate extended hours during declared heat emergencies.
- Any air-conditioned public space. Shopping malls, movie theaters, and large retail stores are effectively cooling centers even when they are not officially designated. Spend the hottest hours of the day there and return home after dark when the apartment has cooled.
- A friend or family member with AC. The best option if available. Air conditioning is the number one protective factor against heat-related illness, according to the CDC.
- A lower floor of your own building. If the lobby or a common area has better ventilation or lower heat exposure, spend time there. A basement laundry room may be the coolest space in the building.
Before you go
Check on your neighbors. Especially the quiet ones.
During the 1995 Chicago heat wave, 739 people died over five days. Many were older adults living alone in apartments with no air conditioning. Their neighbors did not know they were in trouble because they had closed their doors and stopped answering. The people most at risk during extreme heat are often the people least likely to ask for help.
If you live near an older neighbor, a neighbor who lives alone, or a neighbor with young children, knock on their door. Ask if they are okay. Offer water. Tell them where the nearest cooling center is. If they do not answer and you are concerned, contact building management or call for a welfare check.
This takes two minutes. It is one of the most important things you can do during a heat emergency in a shared building.
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