No, if you want to know how your pet feels in cold, go outside WITH your jacket. Dogs wear their jackets 24/7.
I think the article got it right. Going without your jacket is like going out with a shirt and an undershirt on, the equivalent of a dog’s fur. A jacket is just an extra layer.
They didn’t say to go out in the nude, which would be the equivalent of shaving your dogs fur off before they went out.