Verified answer

Whether you get sick or not depends on what the other person has as a sickness.

Mononucleosis and you are probably screwed maybe not in 4 days but a week or more out,

Norovirus screwed even worse and faster

Hep C - not likely to bother you in 4 days but you are in deep poo long term.

A cold - not much to worry about because those viruses usually enter your system by touching an eye or nose with a contaminated hand.

Sick person coveres a lot of possibilities 0 from a cold, to AIDS to Ebola.

Do nothing, you will most likely not catch anything and as you are healthy your immune system will attack any germs you caught any quickly as your are more healthy than the sick person is..

Let's be honest being in the same room and breathing the same air of someone who is sick c an make others sick depending on what they have.