I own to mix cornstarch near dr.smith's diaper cream, how should i store it?

my son had a boil on his butt a week after he be born and the spot has never not here. it's very close to his anus and his ped. have given me all sorts of remedies, some that work for a while and others that just don't. this is our closing option. if this doesn't work he'll enjoy to get it surgically removed. =(
so, my grill is how should i store it? my house is hot inside, we have windowpane units contained by a few rooms but not in the baby's. so it get hot in in that and humid. is that an ok temp. to keep the mixture within? i have the mix surrounded by a baby food jar tightly hermetic but by no means nouns tight. should i keep it by an nouns conditioner too keep it at a lower temp.? my concern is that near the cornstarch it might ferment or something like that near the heat. so what do you suggest i do?
gratefulnessI own to mix cornstarch near dr.smith's diaper cream, how should i store it?
Store it in a plastic jar next to a screw on lid. Like a mayo jar or smaller type jar if you have one. You can get hold of them at Wally world or the dollar shop. It will not ferment.
keep it within a tupperware(or similar) container in the fridge. may be somewhat cold on his bottom, but it's better than surgery.