A Japanese medical expert answers the age-old question for us.

The glorious kotatsu is a beautiful aspect of Japanese culture. If you haven’t heard of it, it’s a low table with a built-in heater under it. By wedging a blanket between the top and bottom table panels you can create a wonderfully warm pocket of heat.

It’s extremely tempting to fall asleep while your lower half is snug in the kotatsu, but it’s a common belief that doing so can cause you to catch a cold. But is there any science behind it? To get to the bottom of it, reporters at online portal Otona Answer asked Dr. Yumie Ichihara if, from a medical standpoint, there was really any relationb between sleeping under a kotatsu and catching a cold.

Ichihara’s response:

There are currently no medical studies on the relation between colds and kotatsu, but I think there is a relation. You become dehydrated when you sleep under a kotatsu. This can cause a dry throat and nose, which increases your chances of catching a cold.

She also goes on to explain the body’s natural cooling system: sweating. When body temperature rises, your body sweats in order to lower body temperature. But if you’re under a piping hot kotatsu, your body temperature won’t lower no matter how much you sweat. Dr. Ichihara explains that this can mess up your nervous system in a bad way.

▼ That’s the spirit, Santa Hat Wearing Guy!

The knowledgeable doctor also busted another myth: isn’t it good to keep your feet warm and your head cool? “Yes,” the doctor explained, “keeping your feet warm can improve your overall system as long as you’re sitting up with just your feet under the kotatsu.” When you lay down and immerse most of your body under the delicious warmth, that’s when things can get a little too heated, literally.

In short, sitting upright under kotatsu: good. Laying down with most of your body immersed under kotatsu: bad. Not only will the dehydration increase your chances of catching a cold, but you’ll also sleep worse since your body can’t cool down to its proper restorative temperature. Take note and resist the temptation, though we admit it is pretty darn hard to fight! That means no sleeping in your personal wearable kotatsu, too.

Sources: Otona Answer via Yahoo! News Japan via Hachma Kiko
Featured image: Pakutaso
Insert image: Pakutaso