hi there , first dont panic ... your plants are nice and young raise the lights a little and give them a little flush with mineral water and they will be fine ,,, i have found that plants in veg can take a lot of abuse ,, as long as they dont get overfeed or have to high temps for to long. in 7 / 10 days you wont even see any damage.. if they were in flower then you might have been realy fucked

get rid of tin foil ,, use white mat paint or mylar instead ,
and dont feed plants till they are nearly ready for flowering
there is enough food in soil for up 2 6 weeks