Not sure why one would want this sort of thing, but as the saying goes, truth is stranger than fiction. I have read the description for these Sauna Pants, and can find no mention of the fact that they vibrate. But I have had two folks claim that they vibrate. Either way, who really wants a hot sauna focused on your genitals? Not me.
If this sort of thing is your cup of tea you can buy them here for about $40. Maybe for a gag gift?