Hey ,

No, Nelly isn’t making a comeback.

But we can definitely learn a thing or two about ideal sleep from his 2002 classic.

If you feel like this:

Then maybe…

Today’s Sleep Destroyer is…

A sleep environment that is TOO HOT

To fall asleep and stay asleep, the body's core temperature needs to drop by about 1 degree Celsius, which is roughly 2 to 3 degrees Fahrenheit. 

That’s why exercise (as previously discussed) too close to bedtime can prevent you from falling asleep, since it raises your core body temperature.

One element that’s essential to reducing your body’s core temperature is a cooler environment.

Cooler indoor temperatures mimic the natural pattern of cool evenings and help signal to the body that night’s arrived and it’s time to sleep.

So is there an “ideal” room temperature to help you fall asleep?

According to Dr. Matthew Walker, there is:

“A bedroom of around 65 degrees Farenheit (18.3 degrees Celsius) is ideal for the sleep of most people, assuming standard bedding and clothing...Of course, that specific temperature will vary depending on the individual in question and their unique physiology, gender, and age.”

While I personally agree with this assessment and love a cold room to sleep in, my girlfriend would beg to differ. 

So as always, my suggestion is to experiment with different things to see what works for you, but this temperature is a good target for the average human being. 

However, Dr. Walker warns, temperatures lower than 55 degrees Farenheit (12.5 degrees Celsius) can be more harmful rather than helpful to sleep.

Okay, but what about if you don’t have air conditioning and it’s the height of summer? How do you cool down then?

Research shows that you can manipulate core body temp through hot baths, showers, or saunas…

While this sounds counterintuitive, a hot bath, shower, or sauna causes blood to rise to the surface of your skin (which gives you a flushed appearance). When you get out of the bath/shower/sauna, the dilated blood vessels help radiate out inner heat quickly, which causes your core temperature to drop. 

This makes you feel more relaxed and sleepier because your core is colder.

Hot baths prior to bed can also induce 10 to 15 % more deep NRM sleep in healthy adults [1].

A counterintuitive hack to drop your core body temperature

An effective way to drop your core body temp and help you fall asleep more quickly is to wear socks on your feet and gloves and your hands.

This causes blood to swell to those areas and draws away heat from your core. 

Scientists experimented with this in a study of young and healthy participants who already fell asleep quickly. 

They warmed their hands and feet by about 1-degree F (0.5 degrees C) and it helped them fall asleep 20% faster [2].

The scientists then repeated this study with a group of older adults who had a harder time falling asleep, and then again with a group of patients with clinical insomnia.

The group of older adults fell asleep 18% faster than usual, and the insomniacs fell asleep 25% faster!

When I first learned about this, the idea of socks and gloves made me uncomfortable, especially in the summer, because I tend to get hot quickly. 

I can’t freaking stand wearing socks to sleep unless it’s cold, but I wanted to try this for myself.

So I wore socks and gloves and left the rest of my body naked (I also had a fan running and used a thin bedsheet in place of a real blanket). 

Guess what?

Even on a pretty hot Southern California summer night, my body actually felt cooler and I knocked out pretty quickly.

(I woke up without gloves and socks, so I must’ve removed them in the middle of the night).

There are also products out there that can help cool you down, such as calling mattresses and blankets, which I’ll get into in the future.

Stay cool🥶

Ready...set...sleep 😴

— Michael, Chief SleepHacker 

PS — One product that’s made a huge difference in my sleep quality (and my performance the next day) are Swanwick Sleep blue-light blocking glasses. I can read on my phone, watch Netflix on my iPad, and even work on my computer right before bed without worrying about my melatonin getting negatively affected. Check them out here*.

References:

1. J.A. Horne and B.S. Shackell, “Slow wave sleep elevations after body heating: proximity to sleep and effects of aspirin,” Sleep 10, no. 4(1987): 383-93. Also J.A. Horne and A.J. Reid, “Night-time sleep EEG changes following body getting in a warm bath,” Electroencephalography and Clinical Neurophysiology 60, no. 2 (1985): 154-57
2. R.J. Raymann and Van Someren, “Diminished capability to recognize the optimal temperature for sleep initiation may contribute to poor sleep in elderly people,” Sleep 31, no. 9 (2008): 1301-9.

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