Is it still cold there?take care not to catch cold. haha

to add something, there's subtle difference between ~죠? and ~요?. ~죠? means you kinda expect them to say something positive about your question. so i would say is it still cold, ins't it? yeah but, not that serious thing

Usually people say 감기 조심해요 when they want to be really polite, or if the want to emphasize the good feelings they have towards you. Kind of like "Take care of yourself!" In English