During sleep, you go through multiple stages. The first stage is where you drift from consciousness into light sleep. Then over the following stages, your body's core temperature needs to drop by about two to three degree before you can reach the state of deep sleep. If your core temperature remains too high, it is hard for your brain to tell if you’re awake or asleep, and this might directly affect the quality of your sleep.
Around 16 to 18 degree Celsius (61 to 65 degree Fahrenheit) is the ideal temperature for your bedroom.
So what can you do to lower your room and body temperature in the hot summer nights, without blasting the air conditioning non-stop?
Open your windows - if your room is warmer than the outside, opening the windows and turning off the light brings fresh air into the room and gives an immediate feeling of well-being.
Get a fan - a ceiling fan gently moves the air, giving a feeling of greater freshness
Drink more water - drink a glass of water before bedtime to get your body hydrated and cool and preemptively replenish the water loss caused by sweating.
Sleep on breathable sheets - cotton sheets, or even better linen sheets, are breathable and absorb sweat so it’s easier for your body to feel cool
Invest in a good mattress - a high quality mattress made of natural materials absorbs sweat and keeps your body at the optimal temperature; when combined with outer layers of linen, cotton and horsehair it provides the best combination to stay cool in the hot summer nights.