I think this ferret is sick, what should I do?

Someone I know asked me to watch her ferret for a week but I found out yesterday that she is in jail for a drug charge and is not likely to get out any time soon. Well at any rate, I live in a basement apartment and the ferret has been down here. Today I noticed that he is wheezing and his nose is kinda runny and his body is warmer than usual. I can't afford to take him to a vet to make sure, but I think he has a sinus infection from being in this basement. However, taking him upstairs in out of the question since both my grandparents are ill and do not want to be around any animals. Is there any place I can take him that will look at him for reduced price, or a place that sells medicine for ferrets? I don't want to get rid of him or send him to an animal shelter just in case his owner gets out of jail.