Please help! Forgot to water corn, dying... Help !!?

I forgot to water my corn stalks (approx 4wks old) Anyways They were doing alright but they've TOTALLY dried up and wilted. I don't know if I should quickily give them a bunch of water or wait until the sun goes down because I know it isn't good to water in the hottest part of day. Please help ASAP. --- What do I do!??