Just recently I got one.
I think I have to get back into the orange juice habit.
So a first step to prevent a cold is to strengthen the immune system. Vitamin c. Also eat bread daily for breakfast. A good breakfast with at least one ounce of whole wheat bread eaten within 7 minutes within the course of the meal will protect you from heat or cold.
But let’s say someone already had a cold. What now?
There are things to avoid – poultry, fat meat, dairy, eggs and nuts. I tried it. It calms the symptoms of a cold. This is what it says in talmud. / Berakhot 57b
Guess it’s also good to stay warm.