火燵掛布[kotatsugake] cover for kotatsu
火燵布団[kotatsubuton] cover for kotatsu
引火[inka] catching fire
引火温度[inkaondo] flash temperature
引火点[inkaten] flash point

曳火弾[eikadan] tracer bullet
煙火[enka] smoke and fumes (e.g. from cooking)
遠火[toobi] distant fire
下火[shitabi] burning low
下火になる[shitabininaru] to be under control

炬燵[kotatsu] kotatsu
炬火[kyoka] pine torch
掘炬燵[horigotatsu] low, covered table placed over a hole in the floor of a Japanese-style room

置炬燵[okigotatsu] portable brazier
炬燵虫[kotatsumushi] someone who curls up under a kotatsu all winter