Thermal environment, specifically the proximal temperature around your body and brain, is perhaps the most underappreciated factor determining the ease with which you will fall asleep tonight, and the quality of sleep you will obtain.
Ambient room temperature, bedding, and night clothes dictate the thermal envelope that wraps around your body at night.
It is the temperature of your room that has suffered a dramatic assault from modernity.
To successfully initiate sleep, your core temperature needs to decrease by 1 degree. For this reason you will always find it easier to fall asleep in a room that is too cold than too hot.
Your nocturnal melatonin levels are controlled not only by the loss of daylight at dusk, but also the drop in temperature that coincides with the sun.
The hands, feet, and head are remarkably efficient radiating devices that, just prior to sleep onset, jettison body heat in a massive thermal venting session so as to drop your core body temperature.
Warm hands and feet help your body's core cool, inducing inviting sleep quickly and efficiently.
The need to dump heat from our extremities is also the reason that you may occasionally stick your hands and feet out from underneath the bed covers at night due to your core becoming too hot, usually without you knowing.
A bedroom temperature of around 18.3 C Degrees is ideal for the sleep of most people, assuming standard bedding and clothing.
A hot bath in the evening and soak the body before bedtime is great to help us fall asleep more quickly.
You do not fall asleep faster because you are hot and toasty to the core, instead, the hot bath invites blood to the surface of your skin, giving you that flushed appearance.
When you get out of the bath, those dilated vessels on the surface quickly help radiate our inner heat, and your core is core temperature drops.
Consequently you fall asleep more quickly because the core is colder.
Hot baths before bed can also induce 10 to 15% more deep NREM sleep in healthy adults.