From what I have seen it all depends on the plant. Certain plants can take higher temps and some can tolerate cooler temps. Just keep a close eye on the plant, you'd be amazed at how they can "talk back" if they dont like something.
well they looked a little pekid, but i turned my heat up before i left again. I also warmed up their water a little before giving it to them. do you reckon that was an ok thing to do?