Angela, Hodgins and others in “The Cold in the Case”

Angela

They're dead when they're frozen, aren't they?

Hodgins

Yes, but they keep oxygen circulating while putting in the cryoprotectants to save the cellular integrity of the remains.

And they use propofol to keep the remains from animating during the process.

Angela

[shocked] Animating? You mean like, the "walking dead"?

Hodgins

[grins excitedly] Yeah, it's actually––

Angela

[cuts Hodgins off] If you say "cool", you won't have sex for, like, a year.

Hodgins

Revolting.