Tartarus may be in another dimension

It is summer, yes? Pretty much no matter where you live in the United States, July and August get pretty warm. Around Tartarus we've had several days in the upper 80's. Why then are all of our coworkers wearing sweaters?

This is what it has looked like all summer

Neppy wears a sweater Every. Single. Day. Heavy, only-wear-it-in-the-dead-of-winter, sweaters. Every day.

Today, Shoes came in wearing a heavy long sleeved sweater. When we saw Shoes 15 minutes later, that sweater had been removed to reveal...

-wait for it-

another sweater.

It's like those nesting dolls. Or Bartholomew Cubbins's Hats. Or Sammy the Dead Rat from Wayside School (look that last one up if you've never heard of it. It's a hoot.)

Are all of these people completely brain dead?