It is certainly very important. Not just for you but for those around you. People can be what we call asymptomatic carriers of a disease. This means that you have the disease but you’re not sick. You are, however, still contagious and can make other people sick.
Of course no one likes being sick so you should try and be healthy for yourself too.
You need to keep your immune system healthy by making sure you are warm, well nourished, and get lots of sleep. You cannot catch a cold from being out in the cold but you can weaken your immune system making it more likely that you will get sick.
It’s also important to keep the rest of your body healthy, regular nutritions meals, regular exercise (doesn’t mean pounding away at the gym, going for a walk or playing some sports with friends counts), lots of sleep and of course everything in moderation!
Mental health is very important too and can often be ignored. We need to keep an eye on both our selves and those around us to make sure they are ok. Remember that if you are having trouble coping with stuff or just don’t feel like yourself there is no shame in talking to a counsellor. It is something that can be very hard to do and doing so is a sign of strength not weakness. It can very good to talk to someone who is not involved and is totally neutral. Mental health can be hidden but is very important so speak up.