Journal
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Why a cool, dark room helps
A cool, dark room helps because sleep starts while core temperature is falling. The heat leaves through the skin, and a cool room gives that heat somewhere to go. Colder is not better. Darkness lets melatonin rise. Bright evening light, including a phone, can hold it back. Sleep starts while you cool down Sleep begins…
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Why you wake around 3 a.m.
You wake around 3 a.m. because the second half of the night is lighter. Sleep runs in cycles of about 80 to 100 minutes, and the later cycles carry more REM, which is easier to leave. It is not a 3 a.m. cortisol spike. Cortisol stays low through the early night and peaks near your…