No other than wilting it's fine. It really seems to be the sun that's
causing the wilting, since since the sun shade's been over it today
it's recovered. Strange that just the one plant of the three in the
container should wilt. It's meant to be hot the next few days (32C) so
I'll observe for wilting. I thought tomatoes can withstand full sun. Or
do they do better with it filtered? Maybe they have to get hardened to
the sun.
Being such small plants I'm sure it's not a watering problem. I'm
suspecting this blossom rot virus since I've had it before. Didn't
think it started as soon after planting out as that though. Only other
thing could be that something's eating the roots, though as I say it
was fresh compost.