The Temperature Trick

To start sleep, your body has to shed about 1 to 2 degrees Fahrenheit of core heat. That's why one of the best sleep aids is something most people get backward: a warm bath, taken one to two hours before bed.

Your room should help that cooldown, not fight it. Keep the bedroom around 65-68°F (18-20°C) and use breathable bedding so trapped heat can escape.