I'd be inclined to treat them as house plants - good soaking beforehand and then standing in the bath on an old wet towel with the tap just dripping to keep the towel damp. I also draw the blind to keep the heat out of the room.

Yes if they are in smallish pots then bring them in as urbanite says.

I would place them against the north wall of the house (total shade), give the pots a good soaking and stand them in a shallow tray with a little water in it.

My idea would be a shady spot outside an old towel well soaked and folded, then a container filled with water and a strip of towel ripped off and suspended from the container to form a wick put the pots and container on the damp towel with the strip of cloth at the bottom of the container and long enough to reach the towel, this system kept my tomato plants alive for a few days

thanks to everyone for the advice - I will do as suggested by bringing them indoors as there is nowhere in my garden that is shaded more than a couple of hours, - also if I left towels and bits out the foxes would demolish them. the little devils.