Annie, Ya it sounds like sun burn. Those cripy leaves will fall off or you can take them off and new ones should replace them. Unless the plant is tooooo small and the whole plant is crispy.

When starting to harden off your plants...place them in a shady spot for an hour or 2.....then bring back in, gradually put them in sun then shade for short periods of time. Each day after add an hour or 2 so this doesn't happen.

Remember we all make mistakes.....its just part of gardening.

Sierra

Your not alone Annie, the same thing happened to some of my tomatoes. They had never seen true sunlight. Putting them out into a couple hours of sun did some in. Oh well, the greenhouses need business too.
Shelley

Well since we are going to be away for 4 days I just rigged up a cover for my greenhouse.
I took an old white sheet and draped it over the top and wrapped packing tape around in about 3 places...
Attractive...No...but lets hope it protects them a bit.
I will leave the top open so the heat can escape...I have left it like that for the last 3 nights and everything seems to be ok...I'll let you know when I get back.

I have been slowly hardening off my tomatoes for a week now. The last two days have been really sunny. I have noticed last night that my tomatoes are slightly sunburnt. I still want to acclimize them to the sun. I was thinking of proping an old window screen over them to filter the sun. Do you think that will be enough? Any other ideas?

I think it's a good idea Kim, on my little cold frame I built I have a glass window over top for cold nights, and a window screen the same size for during the day. I haven't had any problems with scorching inside it. The screen does cast a fair amount of shade.