If you really want to go down the rabbit hole, this is the most complete attempt I’ve seen to rationalize the mess:
http://atavachron.wikidot.com/start
But, yeah, the short answer is that they don’t.
Illogical vulCan Posse
Captain's log, stardate 23.9, rounded off to the nearest decimal point....
Computer, Faygo, hot.
Please specify temperature: Earl Grey hot or sitting in the trunk of your '99 Malibu all summer hot?