1. You can't catch a cold from the cold weather, or if you don't dress warmly in winter. 
Cold and flu are viruses, so you get them from exposure to the viruses, not when you are exposed to the cold weather. You may get a runny nose if you stay outside on a cold day, but you won't get sick from it.

2. You won't get sick if you go outside with wet hair either.

3.  In western countries, mothers and grandmothers love to feed their children with chicken soup when the children have a cold.   The soup is warm, so it makes the children feels better. The chicken soup is not magic remedy.

4.  It has been spread on the internet that rubbing Vicks VapoRub on the bottom of your feet and then wear socks to cover them and go to sleep will ease cold symptoms. 
It is a myth, but some people think it works.  It works better if you rub it on your chest.