Normally Fire-type Pokémon and Pokémon with the Water Veil Ability cannot be burned; however, if a Pokémon is burned then has its type changed to Fire or its Ability changed to Water Veil, the burn will remain.
Fire-type Pokemon also happen to be the only Pokemon immune to the burn status effect!
So according to these sites, Fire types won't be burned no matter what. And also, in all the times I've used Scald and been attacked by that move, my fire type and the opponents' Pokemon have never been burned. So I'm 99.99% sure fire-type Pokemon won't get burned by Scald.