The Old Norse word heitr
Word heitr
h e i t r
Meaning hot, burning

Other words that might be of interest
eisa ‘fire’, eldr ‘fire’, aska ‘ashes’, skírr ‘clear, bright’, døkkr ‘dark’, dimmar ‘dark, gloomy’, myrkr ‘dark, murky’, dimma ‘darkness’, logi ‘flame, blaze’, skuggi ‘shadow’, reykr ‘smoke, steam’, sól ‘sun’, sunna ‘sun’