Overheating is one of the biggest barriers to getting comfortable in bed, which is essential to consistent, high-quality sleep. In its 2010 Bedroom Poll, the National Sleep Foundation found that nearly 70% of people said that bedroom temperature had a big impact on their ability to sleep well.
As a result, on summer nights, or even year-round for people in hot climates, a rising thermostat can make it hard to fall asleep or lead to unwanted awakenings during the night. Knowing how to cool your bedroom, and implementing other tips for sleeping cool, can bring relief and help you sleep longer with fewer interruptions.
How the Body Keeps Cool
The body has an advanced system for regulating its temperature. By understanding how your body naturally cools itself down, you can more effectively avoid sleeping hot.
There are three ways that the body can cool itself down:
- Convection: This happens when air moves heat away from your body. Convection is effective when the room temperature is cooler than your skin.
- Radiation: Radiation relates to how heat moves between your body and nearby objects. When those objects are cooler than your skin, heat from your body will traverse the air between you and the objects to warm them up.
- Perspiration: Sweating is a central way that the body reduces its temperature. Sweat is released onto the skin and evaporates, helping to pull heat away from your body. When there is moving air, it makes sweat evaporate more quickly, cooling you down faster.
A hot room makes it harder for convection and radiation to work. Humidity can also play a role as it slows the evaporation of sweat, making perspiration less effective at cooling you down.
Knowing the Dangers of Heat-Related Illness
Even if you follow numerous steps to keep your room and your body cool during summer heat, it’s important to be aware of the warning signs of heat-related illness like heat stroke and heat exhaustion. If a person is overheating and nauseous, dizzy, or close to passing out, it’s important to get help immediately. Older adults and people with chronic health conditions are at a higher risk of heat-related illnesses.
Tips for Staying Cool During Sleep
If you’ve got air conditioning, it’s a cinch to stay cool when the mercury rises. If you don’t have A/C, knowing how to cool down can be vital to avoid sleeping problems during hot weather.
Two key strategies — limiting heat buildup and cooling things down — are your best bet for keeping your room and your body cool during warm weather even without A/C.
Limiting Heat Buildup
Multiple approaches can keep your home from retaining heat, which makes it easier for your body to use its natural processes to stay cool.
- During the day, lower your blinds and close windows and doors to keep sunlight and hot air from moving into your home. Insulated cellular shades, also known as honeycomb shades because of their internal construction, can block up to 80% of unwanted solar heat.
- Ditch your incandescent bulbs. These light bulbs are inefficient; of the energy they use, only 10% is given off as light while the remaining 90% is heat.
- Decrease the use of energy-intensive appliances. Try to avoid indoor cooking with your oven or stove, both of which give off plenty of heat. Even toasters and microwaves put off warmth, so try to avoid extended use of them. Running other large appliances like washers and dryers can drive up the temperature of your home as well.
- Consider reflective roofing materials and attic insulation. The sun beating down on your roof can heat up your attic, which makes it take longer for hot air to rise and ventilate out of your home. A reflective roof helps keep your attic, and by extension the rest of your home, cooler.
Cooling Things Down
Ventilation is one of the best tools available to cool down a room during the summer without air conditioning. In most climates, it gets colder at night, and during that time, you want to use ventilation to bring as much cool air as possible into your home. Even during the day, ventilation can create moving air that can make your room or home a more manageable temperature.
The following methods can improve your home’s ventilation:
- Creating a cross-breeze in your room: A cross-breeze occurs when there is an entry and exit point for air, allowing wind and the natural movement of air to bring some relief from the heat. To create a cross-breeze in your bedroom, open two or more windows or doors so air can flow in through one and out the other. Feel how the air is moving and adjust the openings to get more airflow. Generally, you want the opening where air is coming in to be smaller than the one where it’s going out.
- Encouraging cross-ventilation throughout your home: Basic cross-ventilation can help cool one room, but you can get even better results by forcing air to move longer distances through your home. An example is the “chimney effect,” which pulls hot air up toward your attic and brings in fresh air from outside. To make the most of cross-ventilation, it helps to consider your home’s layout and ideally have a sense of typical wind directions. You can experiment with different approaches, opening and closing windows or doors to optimize airflow through your home.
- Using circulating fans: Fans can give a boost to ventilation by moving air when wind or natural cross-breezes are limited. Fans of all types can be helpful including table fans, taller floor fans, ceiling fans, and window-mounted fans. If you have multiple fans, you can position them at different windows with one blowing in and one blowing out to strengthen cross-ventilation. While whole-house fans can be expensive, they can strengthen the chimney effect, pulling hot air out through a fan in your attic.
An evaporative cooler takes ventilation to another level by chilling the air before it is distributed through your home. These devices, also known as swamp coolers, cool and humidify air as it enters your home by moving it over a series of wet pads. Evaporative coolers are most effective in dry climates and can be installed in a number of ways depending on the size and layout of your home.
When a full evaporative cooler isn’t in the budget, some people create a makeshift version with a table fan and a tray of ice or ice water. By setting up the fan to draw in air that has been chilled by the ice, you can direct a cool breeze your way. Misting fans offer a similar effect, providing a touch of moist, cool air to the fan’s ventilation.
In addition to cooling down your bedroom, you can employ other tips that can help you avoid sleeping hot even at the height of summer:
- Sleep in loose, lightweight clothing so that air can move around your skin.
- Use bedding that sleeps cool. Sheets made with breathable materials like high-quality percale cotton, Tencel, or bamboo-rayon can help wick moisture away from your body to evaporate and cool down more quickly. For covers, use a top sheet made of breathable materials or a light blanket that doesn’t trap heat.
- Try a cooling mattress pad. Cooling mattress pads help reduce heat retention through their design and materials. The most advanced models pump cooled water through tiny tubes in the pad to lower your bed’s temperature.
- Stay hydrated throughout the day, and sip ice water in the lead-up to bedtime to help feel cool before going to sleep.
- If you share a bed with a partner, try to ensure that there’s enough space between you for airflow around each of your bodies.
- Take advantage of your freezer. Ice packs, especially the kind made to avoid condensation on their exterior, can be used in bed and applied to areas like your head, neck, or wrist to give your body a sense of coolness. A low-cost way to try to recreate this is by moistening a towel or t-shirt and leaving it in the freezer for a few hours. When you need to cool down, you can remove it from the freezer and wear it around your neck or other pulse points.
- Consider taking a cold, refreshing shower as part of your bedtime routine during the summer.
To improve your sleep, it can be helpful to review your sleep hygiene and take steps to address other potential barriers to sleep such as excess screen time, an inconsistent sleep schedule, or bothersome light or noise pollution in your bedroom.
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- 3. National Center for Environmental Health (NCEH), Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Centers for Disease Control and Prevention (CDC). (2017, September 1). Warning Signs and Symptoms of Heat-Related Illness | Natural Disasters and Severe Weather | CDC. Retrieved October 12, 2020, from https://www.cdc.gov/disasters/extremeheat/warning.html
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