Snakes being cold blooded use heat as their metabolism, so think of it as the fuel that lets them do the things we do naturally like think, move, digest food, use oxygen ect. Bumping up temping up their temps pretty much supercharges their bodies. also bumping up the humidity really helps, this keeps their body, lungs, mucus membranes moist and keeps the mucus moist, once that stuff dries it's really tough for their body to expel or absorb think bronchitis with out the ability to cough. Meds will supplement the bodies natural immune system but the environmental things are as big a factor in URI treatment as the meds. Best of luck and keep his water and enclosure really super clean..change the water daily and clean the enclosure every other day. Other than that Leave him be and let the meds do their job.