noun, verbal noun
A fire wound is a burn or scald you got from fire (or other hot things). Ouch!
The reading for this is unlike anything you've seen with these kanji. Try to think about a burn (on your arm) being caused by a yakky dodo (やけど) bird (which is a dodo bird that has yak-like features). Take a look at how weird it is, and wonder why it is burning you. Feel the pain.
I spilled curry and got a burn on my hand.