There's no substitute for experience.
It’s one thing to tell a pair of cats whining to be let outside that it’s wickedly, cat-freezingly cold outside, and that they probably wouldn’t like it if I did let them out.
It’s an entirely different thing to actually open the door and allow them to stick their heads outside, sniff the air, and then have them wheel around without setting a paw outside the door and head back to their respective heating ducts.