THE FIVE: Essential Lifestyle Principles For A Life In Sync
- Yoga: Asanas (Postures) + Pranayama (Breath)
- Meditation + Mindfulness
- Psychic Sovereignty (Our Relationship To Technology)
- Sleep Hygiene
- Outdoor Rituals
Everyone seems to have an idiosyncratic preference when it comes to night time bedroom temperature. Sleep is generally associated with being warm and cozy—but it turns out that being too warm can actually compromise sleep quality.
Sleep researchers have concluded that the ideal bedroom temperature for sleeping is 65 degrees Fahrenheit (18 degrees Celsius). Accounting for personal differences in temperature regulation, a range of 60-67 degrees is generally considered favorable.
Along with minimization of light exposure, proper temperature regulation is one of the most important (and most easily controlled) sleep hygiene practices. Above-optimal core body temperatures have been associated with decreased restorative slow-wave sleep,  time spent in REM sleep,  and sleep efficiency. 
Why Warmer Temperatures Compromise Sleep Quality
As we discussed in a previous sleep hygiene article, our sleep cycle is regulated by our circadian rhythm. Though circadian rhythm is primarily based on the light-and-dark cycle of the sun, temperature is one of the most important cues used by the body clock to transition into sleep.
A lowering of core body temperature tends to coincide with the release of melatonin about two hours before sleep, and this temperature can fluctuate by up to 2 degrees over the course of the night.
If this lowering of body temperature is interrupted by external factors, your circadian rhythm is disrupted, and sleep becomes more difficult. Higher ambient temperatures, excessive sunlight exposure, eating or exercising too close to bedtime, and caffeine consumption can all raise core body temperature and compromise sleep.
A warmer-than-ideal bedroom temperature then creates a sort of vicious cycle (especially if your core body temperature is already too high at bedtime). When you begin to enter REM sleep, most of the body’s temperature-regulating behaviors cease (i.e. sweating, shivering, etc.).  This shift makes you more vulnerable to the ambient temperature of the bedroom, and the resulting rise in body temperature will increasingly lessen the amount of time spent in REM sleep.
You can break this cycle with some simple practices for regulating your core body temperature and the ambient temperature of your bedroom.
Practices for Regulating Core Body Temperature
1. Take a cool shower before bed. Save the full-on cold showers for morning, as lowering body temperature too dramatically can trigger the body’s compensatory mechanisms, which could end up raising body temperature rather than lowering it.
2. Eat your last meal at least 2 hours before bedtime, and try to eat light. Digestion raises body temperature, especially after heavy meals (so it’s best to save those for earlier in the day).
3. Stop exercising at least 3 hours before bedtime—this will help you align with your natural circadian rhythm (and its accompanying drop in body temperature as bedtime approaches).
4. Cool your pulse regions with ice packs or wet washcloths. Even a quick application on your forehead and wrists can work remarkably well.
5. Stay hydrated. Obviously, drinking too much water right before bedtime will have you visiting the bathroom in the middle of the night, but even mild dehydration can disrupt your body’s thermoregulation.
Practices for Regulating Bedroom Temperature
1. If you have a central climate control system, keep the thermostat at 65 degrees F (or even as low as 60 degrees, if you tend to run hot). Try out a few different settings in the range of 60-67 degrees, and monitor which one allows for the highest perceived sleep quality.
2. If you don’t have a central cooling system, consider investing in an air conditioner, or at least a high-quality fan.
3. If the air temperature outside is 65 degrees or cooler, open your bedroom window.