Seems like a little more than forgot to turn on the AC to me, but however it happened it is a tragedy. Hopefully you will automate and standardize your process as much as possible so "forgetting" can't happen in the future. Power up the lights in an empty room and take measurements for a day before moving the ladies, maybe?
I feel like your grow's scale is out of whack with your attention to detail, or this wouldn't have happened. Try again, plant killer. I have killed plants too, but you earned that.
I wish you well in your future grows. At least they weren't a week or two from harvest, you could have lost more time and energy than you did.