Is this the hot weather?

Hey just after a bit of help, the box has consistently ran around 25-26c until yesterday temps were touching 28-29. I have rectified this now but a lot of the top leaves are taco-ing slightly. I'm just after a conformation of this really lol. And to know how long till they uncurl? First pic is from the day before is started happening and the one below is the current situation. Thanks

Minor heat stress usually recovers overnight if plants have adequate water.