The question of whether sleeping without a blanket is better does not have a single, universal answer. The optimal sleep environment is a personal balance between physiological necessity and psychological comfort. While the body’s biology favors cooling for sleep, the need for security often introduces a preference for cover. The “better” choice depends on an individual’s unique needs, room conditions, and relationship with warmth.
Core Body Temperature Regulation
Initiating sleep requires the body to shed heat and lower its core temperature by approximately 1 to 2 degrees Celsius below its daytime peak. This core temperature drop is a fundamental part of the circadian rhythm, signaling the brain that it is time to rest. The body achieves this heat loss primarily through peripheral vasodilation, where blood vessels in the extremities, especially the hands and feet, widen.
Vasodilation allows warm blood to flow closer to the skin, where heat is efficiently dissipated into the cooler air. Blankets act as insulation, trapping heat near the body and hindering the natural heat-loss mechanism required for sleep onset. Sleeping uncovered maximizes the surface area exposed to ambient air, facilitating faster heat dissipation and potentially reducing the time it takes to fall asleep. The rate of peripheral heat loss is considered a reliable predictor of how quickly a person will drift off to sleep.
The Psychological Need for Weight and Cover
Despite the physiological drive toward cooling, many people find it difficult to sleep without the weight and security of a blanket. This psychological need is rooted in deep pressure stimulation (DPS). DPS involves applying firm, consistent pressure to the body, similar to being swaddled as an infant or receiving a tight hug.
The physical sensation of a blanket’s weight activates the parasympathetic nervous system, which is the body’s “rest and digest” mode. This activation helps shift the body out of the “fight or flight” state, promoting a sense of calm and safety. The pressure encourages the release of feel-good neurotransmitters like serotonin and helps reduce the stress hormone cortisol, making it easier to quiet an anxious mind. For these individuals, the grounding effects of a blanket often outweigh the slight delay in sleep onset caused by insulation, making the covered state feel more restful.
Health and Environmental Considerations
The decision to use a blanket must be adapted to specific health and environmental circumstances. In cases of illness, such as a high fever, the primary goal is to help the body dissipate excess heat. Covering up too much during a fever can trap heat and increase discomfort, making lightweight or no covering the preferable choice.
Individuals dealing with inflammatory skin conditions like eczema should prioritize a cool sleeping environment to prevent overheating. Overheating causes sweating, and the salt in sweat can intensely irritate inflamed skin, worsening the itch-scratch cycle and disrupting sleep. A cool room temperature, ideally between 60 and 67 degrees Fahrenheit, is recommended for optimal sleep quality, and a blanket-free approach supports this. Conversely, people who naturally run cold or use a very cool room may need a lightweight blanket to prevent shivering, a heat-generating response that counteracts the goal of cooling. Layering, using a light sheet or breathable cotton blanket, allows for easy adjustment to maintain the balance between the physical need to cool down and the psychological need for comfort.