Aloha,
Assuming you're talking BB's I know a couple have asked but I haven't seen your reply. Are you running the "Fire Prevention" or "Basics of Survivability" skills? As a DD main I pay attention to BB's that I see hitting their DC as soon as a fire starts... that shows me they enjoy being toasty...
My advice as Hapa the player:
A: Get those skills. (FP and BoS)
B: Ignore the first fire (don't DC) and if it's early in a battle, you have the HP to spare and aren't tightening your chin strap and pushing in, ignore even a second (because Repair Party)
I have been in battles where I can tell all the BB's have Fire Prevention... How? I could have like 300 HE gun hits and single-digit fire amounts. (well either that or RNGeezus didn't like me that fight).
I hope you are getting some assistance in this post!
Mahalo,
-Hapa