The Best Temperature for Sleep—and Why It Matters

Sleep and temperature are closely connected. Your core body temperature follows a circadian rhythm and generally declines around the transition into sleep. At the same time, changes in skin blood flow help your body transfer heat from the core toward the environment.

Think of it less as “your body needs to become cold” and more as “your body needs to be able to regulate and release heat.” Your bedroom is part of that process. So are your sheets, comforter, pajamas, mattress, mattress protector, partner, airflow and humidity. Together, they create the sleep microclimate surrounding your body.

That's why two people sleeping in the same 68°F bedroom can have completely different experiences. Research reviews of sleep environments emphasize the importance of this thermal microclimate as well as individual physiological and environmental differences.[2]

You'll often see recommendations online suggesting that the ideal bedroom temperature is somewhere in the 60s. That's a reasonable range to experiment with for many adults, but the scientific literature doesn't establish 65°F as a universally optimal thermostat setting.

A 2024 systematic review of real-world studies concluded that higher ambient temperatures were generally associated with worse sleep quality and quantity. But real-world evidence also shows substantial individual variation.

In one longitudinal study of older adults, sleep was most efficient and restful between approximately 68°F and 77°F. As bedroom temperature increased from 77°F to 86°F, sleep efficiency declined by a clinically meaningful 5–10%.

Again, that doesn't mean 72°F is the new perfect temperature. It means: extreme heat is generally bad for sleep, while comfortable temperature varies by person and circumstance.[3][1]

Suppose your thermostat reads 67°F. You climb into bed wearing long pajamas, underneath a sheet and down comforter, on top of a foam mattress. The room air is 67°F. The environment immediately surrounding your body isn't.

Bedding and sleepwear affect insulation, moisture movement and thermal comfort. A 2024 systematic review found that fiber choice can influence some sleep outcomes under particular conditions, but the studies were relatively small and varied substantially. There wasn't one material that emerged as universally best.

That's why simply lowering the thermostat doesn't always solve a hot-sleeping problem.[4]

This is common. The traditional solution is compromise: one person is too hot, the other is too cold, and neither is particularly happy.

Before buying technology, try separate blankets. Each sleeper can control insulation independently while keeping the room at the same temperature. If the difference is substantial, dual-zone bed-level temperature control may become more interesting.

No. This is another place where consumer sleep advice gets oversimplified. Excessive heat can disrupt sleep, but being uncomfortably cold isn't the goal either. Thermal comfort depends on the interaction between room temperature, bedding, clothing and the sleeper.

The practical target is: cool room + comfortable bed, rather than: make yourself as cold as possible.

If you're not waking hot or cold and you're sleeping well, don't change your bedroom because an article tells you 65°F is “better.” If you're waking because of temperature, experiment systematically.