Sick Tomatoes

Today has been hot (if you have been in a cave somewhere all day and didn't notice) and when I got home the heat and boiled off ALL the watering that I did last night (on the lettuces mostly) but also the tomatoes that I had left in the little greenhouses were all looking rather limp.

A very sad looking tomato plant :(

I pulled them all out to water them and, while I was doing that, I noticed that a number of them had white patches on their leaves.

Tomato plant with white withered patches

I've never seen these before, and am not totally sure what to do.

In summary, I have now lost one more seedling, another couple (one previously pictured) are looking seriously the worse for wear, and they are ALL now inside again as I prepare them to be given away to people.

Today I gave three plants away, and yesterday I gave away five. Tomorrow I have ten to take into work for various people, and I have got seventeen more to offload in my list so, if you do want any, shout soon as I may actually run out of healthy plants to give away...

In other matters, I think my mint is sprouting, I have been using my hose to water my plants today and SAVING water (not sure what the hose pipe ban is all about when water is scarce; using a watering can takes FAR more!) and all my own tomatoes are growing well (including a runt which I thinned from a pot and just stuck in the soil!)

So yeah, any advice on the white patches will be gratefully received.

Edit: I have been advised to stand the plant pots in a bowl of water, rather than watering from the bottom up (this is for the wilting) I have also done the same with the particularly bad white-patched plants... Thanks to @Dracunculus2010 for the really quick response on this :) any more advice still gratefully received tho :)


Edit 2: Thanks (as per) to @andyfereday67 he is sure the white patches are "scorch" marks so the same treatment is prescribed; shade the plants, keep them watered etc etc... thanks :)