How to sleep in a heat wave without AC: Experts reveal when to stop using a fan and the simple bathroom hack that helps

When temperatures stay high after sunset, getting a good night's sleep can feel impossible—especially if you live in an older home or apartment without central air conditioning. Across the U.S., more families are searching for low-cost ways to stay comfortable while keeping electricity bills under control. One surprisingly effective trick doesn't require a new appliance or expensive gadget.

All you need is a clean bathroom towel, cool water, and a fan used under the right conditions. While this simple method won't replace air conditioning, experts say it can make your sleeping space feel more comfortable. Just as important, health officials warn that fans are not always safe during extreme heat, making it essential to know when this cooling hack works—and when it's time to find a cooler place.

Can a damp towel really make your bedroom feel cooler?

The towel trick is based on a basic scientific principle called evaporative cooling. Start by soaking a clean towel in cool water and wringing it out until it is damp but not dripping. Hang it near an open window or place it in front of a fan so air moves across the wet fabric. As the water slowly evaporates, it absorbs heat from the surrounding air, creating a cooler breeze in the immediate area.

This method works best in dry or moderately humid climates where evaporation happens more easily. It will not lower the temperature of an entire room the way an air conditioner does, but it may help cool the air around your bed enough to make falling asleep easier.

Another option is to place the cool, damp towel across your neck, wrists, or feet for several minutes before bedtime. These areas help your body release heat more efficiently, offering quick but temporary relief on warm nights.

When should you stop using a fan during extreme heat?

Fans are one of the most common ways Americans try to beat the heat, but they have limits. According to the U.S. Centers for Disease Control and Prevention (CDC), electric room fans should not be relied on when indoor temperatures climb above 90 degrees Fahrenheit. At that point, fans may simply circulate very hot air, making it harder for your body to cool itself and potentially raising your core temperature.

The World Health Organization (WHO) sets an even higher threshold, advising that fans may no longer provide safe cooling when indoor temperatures exceed 104 degrees Fahrenheit.

If your home reaches those temperatures, experts recommend moving to an air-conditioned location such as a public library, shopping mall, community cooling center, or another public building with climate control. Staying hydrated and limiting physical activity are also important during periods of dangerous heat.

What other simple habits can help you sleep comfortably without AC?

The towel trick works even better when combined with a few other easy changes around your home. Keep blinds and curtains closed throughout the afternoon to block direct sunlight from heating your bedroom. Once outdoor temperatures begin to drop after sunset, open windows to let cooler evening air circulate if conditions outside are comfortable.

Choose lightweight cotton sheets instead of heavy blankets, as natural fabrics allow heat and moisture to escape more easily. A cool shower before bed can lower your body temperature and help signal that it is time to sleep. Avoid using ovens, clothes dryers, or other appliances that generate extra heat during the evening. Even unplugging unnecessary electronics can reduce the amount of heat building up inside your bedroom.

People who are older, very young, pregnant, or living with chronic health conditions should take extra precautions during heat waves because they are more vulnerable to heat-related illnesses.

A damp towel may sound old-fashioned, but it remains one of the simplest ways to make hot summer nights more bearable when air conditioning isn't an option. Combined with safe fan use, proper hydration, and smart cooling habits, this inexpensive bathroom staple can help create a more comfortable bedroom. Before you head to bed tonight, check the indoor temperature, use fans only within recommended safety limits, and try this easy cooling trick to stay more comfortable through the night.

Long before air conditioning existed, people across the United States and Europe relied on simple but surprisingly effective ways to stay cool during extreme summer heat. Homes were kept closed during the hottest hours of the day by shutting shutters, curtains, and windows to block direct sunlight, while windows were opened after sunset and before sunrise to let cooler air circulate.

Many families hung damp cotton sheets or towels near open windows to create a mild evaporative cooling effect, slept on lightweight linen bedding, and avoided using ovens or fireplaces until evening to reduce indoor heat. Thick stone walls, shaded porches, high ceilings, and strategically planted trees around homes also helped keep living spaces naturally cooler.

Drinking water regularly, wearing loose, light-colored clothing made from natural fabrics, and limiting strenuous outdoor work to early morning or late evening were long-standing habits that remain practical and effective during today's increasingly frequent heat waves.