He catches a cold

When my friends tell me they don’t go near babies when they have a cold, as the baby may catch it, I didn't get it. How can a 2 month old catch a cold? Does he continuously sneeze? Does his nose drip?

I found out when the boy caught one. None of the above symptoms but his nose was blocked, breathing was difficult and the nights were tough. He could not sleep well and his breathing was heavy. We decided to wait it out a bit