been wondering this for a while: do people really catch colds just by getting wet or sleep...

it's a japanese thing. only someone with a ridiculously compromised immune system would get a cold just because they slept with wet hair. Having wet hair and then going outside may cause hypothermia though, which, back in the days of no temperature control, may have been an issue and is probably when the folklore started.

eh I'm not Japanese but I have gotten a cold by getting my hair wet in the rain and not drying it. The first time it happened I thought it was a fluke then it happened again boom cold and fever...otherwise not sick for years *knocks on wood* :)

As a Canadian who lives and has lived in Canada, the land of snow, my entire life I can guarantee there is no correlation between having wet hair and getting a cold. I frequently have and still do go outside right after a shower even in winter time and I have not once gotten sick. The only kind of sickness you can get from the cold is hypothermia. People correlate illness and cold weather because when it's cold people stay inside more making it easier for germs to spread. There's a youtube video busting this myth, look it up if you are interested in learning more.

While you do not get a cold from being cold, there is evidence that shows that viruses are more active in the cold, therefore making it easier to infect individuals.

I think it depends on the persons immune system. I braid (either french or Wendy style braid) my wet hair and go to bed and I've never gotten sick from it. although my mom (who works in the medical field) tells me to shower before I go to bed so I don't get sick.

yeah its strange...this is normally not the case. I just get a fever after i was thrown into the pool with my clothes on and it was a bit cold outside...would never get a fever just because of wet hair hahah

well im from a city that rain make people go bald so, i always go sick when its raining, japan is a cool country so maybe they freeze very easily with wet hair?

in my case, ive never catch a cold with that, but as i grow(means that happends after you get older), when i sleep with wet hair, sometimes i get a headache and for the jap ppl, is probably due to the low (not freez)temperature of their country

Different people different body protection . Like me , I caught a cold just by touching a few drops of rain . Though if I happily bath in the heavy rain , I won't catch a cold . Like my cousin , he once caught a cold and had to be sent to the hospital . It only happens like 6-8 yrs once , if not careful . So whenever he catches a cold that means terrible death if we don't bring him to the hospital . While on the other side , nobody gives a fuck when I catch a cold . Got the different now ? Plus , this is just a manga . It's created for the plot , duh .

I've tried getting a cold after being stuck in the rain. But getting colds doesn't really have anything to do with the water as such. It's about your temperature changing fast. Of course if your clothes is soaked, you will get cold. Athletes who has been running will also put more clothes on when they're done even though they feel warm because the temperature changes otherwise can make them ill.

I think it is a matter of the person´s constitution but anyway sometimes I do catch cold when I dont dry my hair

lower body temp can compromise a person's immune system. this is the only way someone can get sick. for me, i have never gotten sick for this reason. its always been an over exposure to sick people due to caring for my family members (all of whom DO have less strong immune systems than i do). so, in conclusion, being cold simply raises one's CHANCES of getting sick, not necessarily guarantees it as manga tends to suggest.

Last night I went to sleep with wet hair (I didn't managed to dry them properly). I can assure you that the only thing that happened is that my hair are a shit now wtf. Neither my cold worsened!
I've asked myself the same question everytime I've read about a character that chatched cold/flu just because he didn't dry his hair!!

It's happened...to me (every time)
I will catch cold or got high fever if i don't dry my hair....