system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do feel more comfortable sleeping with our entire body in the blanket/sheets? Is there some psychological aspect behind it?
gpt
Among many other reasons biologically, our core body temperature tends to drop when we fall asleep; so having something to bundle up in (blankets, sheets) helps keep our body temp regulated and also allows our brain to recognise we’re in sleep mode so it can produce yummy relaxation chemicals like serotonin and dopamine.

If we didn’t have something to bundle up in, we lose our ‘microclimate’; when this happens, we become more susceptible to sleep disturbances like temperature fluctuations and other environmental factors like noise and light.