Drooping Plants

I had two very healthy plants growing in a hydro setup and they got to be about 2-3 feet tall and looked perfectly healthy until one day I walked into the room and I found one of my plants drooping. I don't remember doing anything different before it started drooping and I wasn't able to recover the plant, it died. I just walked into the room today and my other healthy plant is now drooping. How do I stop it from dying and prevent this from ever happening again?

I will also include some facts: I have the plant on a 12/12 light cycle. When the lights are off it's about 80 degrees F, and when they're on it's about 90 degrees F in the room. I usually spray water on the leaves to keep they're temperature down. Humidity is usually about 35%. When I walked into the room today, the lights were on and my thermometer read 96 degrees and 44% humidity. I have a balanced pH and I measure the nutrients according to the directions before I put them in, so that shouldn't be the reason.

what type of hydro setup, how often you water, 96 is really hot, you should atleast try to get it in the 80s

Ya, it usually doesn't get quite that hot. The space that I have it in doesn't let heat escape too well. I have a drip bucket hydro system and I usually add water every 2-3 days.

you mean you top off the buckets every 2-3 days or you water your plants every 2-3 days?

I top off my buckets every 2-3 days and make sure they're at the proper level. It's marked on the side of the bucket.

How can I reduce the heat? Put in more circulation fans? Decrease the wattage? Maybe get a water cooled light?

Thanks for the help.