It's a written iron clad law in the attraction universe:

You have to make moves while the iron is hot because if you wait too long, the iron cools off and her attraction plummet's. And when it's gone, you're now forever in the friend zone. I think a woman doesn't look at a man romantically until things get sexual.

I read all the time on the dating subreddits of a guy who meets a woman, they get along great, but a few dates go by where he doesn't make any moves and then he gets the "friendship" text. And it hurts him greatly knowing something awesome slipped right between his fingers.

At the same time, you don't want to make moves before the iron is even warmed up in the first place. A lot of inexperienced men have the mindset of "shit I have to escalate right now to build attraction," so on the first date they're pawing away at the girl, and she just wants to gtfo of there because she's not even comfortable yet. No one wants a tongue shoved down their throat if they're not feeling comfortable and safe yet.

You have to strike when the iron is hot. Not before it's even warmed up and definitely not after. Even the most awkward dude of all time knows when it's hot. That's when you want to strike.

I personally believe it'll naturally warm up on it's own as long as she naturally likes you, but when it is hot, it's only going to be hot for a short period of time.