we were given a third kitten and it was our first time not adopting from a shelter. Echo has a vet appointment tomorrow morning ( soonest we could get him in ) and he's totally got an upper respertory infection. Has sneezing, runny eyes and nose. What can I do to make him more comfy til his vet visit tomorrow? He's still playful and eating and drinking but I just want to do whatever I can to help him?