Toms are curling up?

My toms are starting to curl at the top instead of growing straight, whats wrong with them?

 

Toms can curl and/or twist their leaves if they are stressed, it doesnt take much.
Overwatering or irregular watering, overfeeding, large day/night temperature swings to name but a few.
If they were growing ok upto now, its likely to be that "something" has changed ie; you repotted them recently or increased feed strength etc.

 

I think its been this hot weather weve been having, 10 degrees at night and then 40 degrees by 8am, a good 25/30 degrees during the day. Its only on two plants though.

 

Hi Kev,
My beefsteak leaves were like corkscrews last year with the irratic weather, rain cold etc. The tumbling toms were fine and only some of the red pears were affected so i guess some plants stress easier than others. Are yours all the same variety?