How to Get Better Sleep in a Cool Room

Want great health? Well, then, you need great sleep. It’s essential. And you can’t substitute coffee for sleep. Nothing really substitutes for sleep, try as we might. But did you know, too, that the temperature of your bedroom significantly impacts how well you sleep? Research (and maybe your own experience on a hot summer night) has consistently shown that a cool room is what works best for our bodies to get deeper and more restorative sleep. In this article we’ll explore how temperature affects sleep. We’ll look at a couple of studies that have shown the benefits of a cooler bedroom. And we’ll finish up with some inexpensive solutions, and a couple of high-end ones, too, for keeping your bedroom cool, even on those blistering hot nights on the top floor of your house.

How Temperature Impacts Sleep

Your body’s core temperature drops towards the evening, as part of your body’s circadian rhythm signaling that it is time to rest. A cooler bedroom helps you cool down so you fall asleep faster and stay asleep longer. On the other hand, a room that is too warm can disrupt this process. Restlessness, frequent awakenings, and reduced time in deep sleep stages results from this inability to cool down. You miss out on your slow-wave-sleep and REM sleep, which are critical for physical recovery, memory consolidation, and overall brain health.

While excessive heat can increase restlessness and frequent awakenings, overly cold temperatures aren’t great either, and make it hard for some people to sleep. The ideal temperature range for most adults is between 60°F and 67°F (15°C to 19°C). Of course, there’s exceptions to any generality, so it may be different for you. This Figure from a recent review on temperature and sleep shows you ideal room temperature range and also the microclimate right around your skin. Both are important.

Scientific Evidence on Cooler Sleep Environments

Here are three studies that highlight the benefits of sleeping in a cooler room:

1. Large-Scale Study on Bedroom Temperature and Sleep Quality
   A 2020 study analyzing over 3.75 million nights of sleep data from 34,096 individuals found that bedroom temperatures above 70°F (21°C) were associated with poorer sleep quality and increased wakefulness, even within the recommended range. The researchers concluded that keeping bedrooms cooler, ideally between 65°F and 70°F, optimizes sleep duration and efficiency.
2. Local Body Cooling in Hot Environments
   A 2018 study published in Indoor Air tested local body cooling (e.g., cooling the head and neck) in a hot environment (86°F or 30°C). The study found that targeted cooling improved sleep quality by reducing thermal discomfort, decreasing sleep onset latency, and increasing sleep efficiency compared to non-cooled conditions. Participants reported feeling more comfortable and experienced less nighttime wakefulness.
3. High Heat Capacity Mattress and Slow-Wave Sleep
   A 2018 study published in Physiology & Behavior investigated the use of a high heat capacity mattress designed to enhance conductive heat loss. The results showed that sleeping on this mattress in a warm environment (around 77°F or 25°C) increased slow-wave sleep by approximately 20% and reduced core body temperature, leading to deeper and more restorative sleep compared to a standard mattress.

The importance of maintaining a cool bedroom to maximize sleep quality, reduce wakefulness, and support overall health is supported by these studies and many more.

Budget-Friendly Ways to Cool Your Bedroom

You don’t need to spend a small fortune just to make your room cooler. Here are some fairly affordable strategies to keep your bedroom cool, even during the hot summer nights.

• Get Some Summer Sheets: Swap out the heavy comforters from the winter months for breathable materials like cotton, linen, or bamboo sheets. These fabrics wick moisture and promote airflow, keeping you cool. Look for sheets labeled as “cooling” or with a low thread count (200–300) for better breathability.
• Use Fans to Your Advantage: A pedestal or ceiling fan can significantly lower perceived temperature by increasing air circulation. Where I live the nights are cool, often in the low 60s, so a box fan in the window does the trick. If you aren’t so fortunate (looking at you southeastern states!), place a bowl of ice or a frozen water bottle in front of a fan to create a DIY air conditioner. Just be sure to not point the fan directly at you so you don’t get chilled.
• Block Heat During the Day: Use blackout curtains or breathable blinds to block sunlight and prevent heat buildup. Open windows in the evening or early morning to let cooler air in, especially if you live in an area with cooler nights. We live in a place where this works and it is safe to do this.
• Optimize Sleepwear and Bedding: Wear loose-fitting, breathable pajamas made of cotton or moisture-wicking fabrics. Sleep with a thinner blanket or just a sheet to reduce heat retention. You want a cocoon of warmth for great sleep, but overheating is “no bueno.”
• Adjust Your Thermostat: If you have a programmable thermostat, set it to lower the temperature by a few degrees at night (e.g., 60°F–67°F). This is energy-efficient and aligns with your body’s cooling needs.

These methods are accessible and effective. Get creative. There are probably even more solutions for your situation that will make your room cooler without spending much money.

High-End Tech-Based Cooling Solutions

If you are willing and able to invest in some cool tech, there are a few companies that have put together some awesome ways to regulate temperature so you can sleep better.

• Cooling Mattress Pads and Toppers: Active cooling mattress pads, like the Chilipad Dock Pro or Eight Sleep Pod, use water or air circulation to maintain a precise bed temperature. You can use one of these systems to set the temperature on each side of the bed (from 55°F–115°F) so that the system works for couples with different preferences. Some models include smart features like biometric tracking for sleep optimization. A 2022 study by Eight Sleep researchers found that their cooling mattress pads reduced the severity of hot flashes and night sweats, improving sleep quality for hot sleepers. Cost: $500–$2,000 depending on the model.
• Room Air Conditioners: You could get a high-efficiency window or portable air conditioner to help maintain a consistent bedroom temperature. The AC also pulls water out of the air, which really helps in humid climates. Get a unit with high energy efficiency ratios (EER) to reduce your electricity costs. Cost: $300–$800 for a quality unit suitable for a bedroom. These window units can be pretty noisy though, in my experience.
• Advanced Bedding with Phase-Change Materials: Some premium sheets and mattress toppers use phase-change technologies (e.g., Outlast or 37.5) that absorb and release heat to maintain a stable body temperature. Of course, these are most costly than standard cooling sheets, but they do regulate temperature better, too, Cost: $100–$300 for a sheet set or topper.

Steps to Make Your Room Cool

• If you haven’t tried this already, get your room temperature down to about 65°F. You can adjust it a bit for your own liking. Infants are horrible at keeping bedding on, and they do better with a slightly warmer room (65°F–70°F) to avoid fussiness. Some older adults like it even warmer, even up to 77°F. There is less cardiovascular stress with a higher temperature apparently for them.
• Depending on your budget, pick one option to make your room cooler. A fan and dehumidifier might be all you need. Do you have money for the ultimate sleeping solution? The Eight Sleep Pod or the ChiliPad system look like great options. The law of diminishing returns applies here. You get the most benefits from the first, simplest things you try. Get the basics right first before going pro.

Summing it Up

A cooler bedroom can make a significant improvement in your sleep quality, compared to a hot room. It will help you fall asleep faster, stay asleep longer, and wake up more refreshed. The evidence from many studies across many countries and environments confirms that we humans do well with temperatures between 60°F and 67°F for sleeping. The cooler temperatures enhance REM and slow-wave sleep, support deeper sleep, and even reduce the risk of metabolic disorders. You can use affordable solutions like fans, breathable bedding, or invest in advanced options like cooling mattress pads or smart air conditioners to help create the perfect sleep environment.

People are finding out more and more that skimping on getting a good night’s rest just isn’t worth it. Your days go much better if your nights are filled with deep, restorative sleep. And a cool room is part of the puzzle towards that end. So, if you are struggling to sleep in a hot room, pick one of these tips to try to get some relief and enjoy the restful, rejuvenating sleep that you need.