For the fever, I can't recommend any PD because it's a Sunday so most of them are closed - but you can continue giving fever meds from KKH if they were opened less than 6 months ago :)
To help him, you can continue sponging him, keep him in cool clothes (like shirt and shorts that's not too thick) and let him cuddle/hug as much as he needs! Keeping him hydrated would be important too.
As for the rash, you can try Desitin for the diaper rash - but only apply it on the places with rash because it's medicated. It'll also help to clean with a damp washcloth then air dry before changing diapers, and change it more regularly!
Munchkin Pumpkin