Ever notice how a cold office seems to leave you ready for nap time? Researchers have found that cooler temperatures do indeed appear to help us get deeper sleep, and fall asleep faster. Plus, nothing feels as dreamy as wrapping up in warm blankets in a cold room. Why does this work? Well, as our circadian rhythms approach the sleep phase, our body temperature drops slightly, and stays lower until a couple of hours before you normally wake up. One Australian study found that insomniacs tend to feel warmer in the evenings due to the inability to maintain their core internal body temperature, which may play a role in their inability to fall asleep.

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