The Heat Miser is a character from The Year Without a Santa Claus. He lives in a volcano and controls the hot weather around the earth. He and his stepbrother Snow Miser are the offspring of Mother Nature. (It should be noted that both Snow Miser and Heat Miser were not featured in the original poem that the special is based on.)

It is shown that Heat Miser is able to melt things with a touch, even objects that should combust, like a shovel's wooden handle. However, it is not shown if he can restore objects he melts like Snow Miser can with objects he turns to snow. He can also project intense heat from his mouth and fingers at will, even forming objects of flame that can endure independently for a few seconds. He also sings about his preference for hot weather. His mean, grumpy, hot-tempered personality comes from the fact that he feels that Santa Claus is unfair to him by giving Snow Miser lots of publicity while he gets none, and he believes that Mother Nature likes Snow Miser better.

Although Heat Miser lives in the southern hemisphere, he and his brother regularly patrol the border of the North Pole. At one point, Heat Miser attempts to destroy Jingle, Jangle and one of Santa's reindeer, Vixen. With a flash of heat lightning, Heat Miser strikes them out of the sky, but the trio survives.

The elves later accompanied Mrs. Claus to his lair within an active volcano to negotiate a deal for the weather in Southtown. Unwilling to cooperate, Heat Miser was summoned to the realm of Mother Nature and forced to compromise the weather with his brother for one day.

Heat Miser has a flair for the dramatic, and entertains his guests with a dance backed up by his minions who look just like him, but smaller and in clothes that resemble yellow footie pajamas.