It's not heat stress, heat stress makes the leaves curl up into the shape of a canoe, this is why it's coined canoeing.
It looks like what's called clawing, and from what I gather that's from an abundance of nitrogen, and the tiny tip burn kinda confirms that. You're so far intO flower any problems youll run into won't have Time to fuck your grow, except nanners of course. Looks good, I'd reveg and take a cut off her if I were you. But next time, don't top so close to flower, you killed your yeild because you topped her so late