I've tried looking for an answer to this, but I can't find it. If it's been asked before please redirect me to it.
I've never found out myself since Scald KOs Fire types pretty quickly.
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.
Bulbapedia
Fire-type Pokemon also happen to be the only Pokemon immune to the burn status effect!
Smogon
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.
From my source of Scald theres nothing about it that says about it burning fire types so i'm gonna go with NO