Heat Wave

First time growing outdoors and we're entering a heat wave, well a heat wave for Ontario anyway. It's 90*F today and going up to 100* in the next couple of days.
Not very humid though which is odd for here, only 31% now.
Anyway I moved two plants outside a week ago and they’re doing really well so far. Today they seem to have a little heat stress so I moved them under some shade. I assume this is what the leaf cupping is from? Their soil still has water

.

Is this something I should even be concerned with? Not sure how much abuse they can withstand outside.

They do look heat stressed. I would probably try to keep them from direct sunlight until it cools off a bit.