'Heat' in the Bible

a wild donkey accustomed to the desert, sniffing the wind in her passion. When she's in heat, who can turn her away? None of the males who pursue her need to tire themselves out, for in her month they'll find her."

He will be like a tree planted by the water that sends out its roots by a stream. He won't fear when the heat comes, and his leaves will be green. In a year of drought he won't be concerned, nor will he stop producing fruit."

Therefore, this is what the LORD says concerning Jehoiakim, king of Judah, "He will have no one to sit on the throne of David, and his corpse will be thrown out to rot during the heat of the day and the frost of the night.