Heat etymology in English

English word heat comes from Proto-Germanic *haitaz (Hot.)

Dictionary entry	Language	Definition
*haitaz	Proto-Germanic (gem-pro)	Hot.
*haitijaną	Proto-Germanic (gem-pro)
hǣtan	Old English (ca. 450-1100) (ang)
heten	Middle English (1100-1500) (enm)
heat	English (en)	To arouse, to excite (sexually).. To cause an increase in temperature of an object or space; to cause something to become hot (often with "up").. To excite ardour in; to rouse to action; to excite to excess; to inflame, as the passions.. To excite or make hot by action or emotion; to make feverish.

Heat etymology