I'm worried about my own helis living in such a hot, wet environment...no rotting yet, but I do drain them of water every week or so (by evaporation or just tilting the terra) before getting submerged again with a watering in their terra. It gets really really roasting in a terra in the sun...I end up having to fan my plants during the day and mist them down at the end of the day when it gets really sunny. They're covered in water and sit in a water reservoir to keep the roots cool (the water cools down at night), which seems to be sorta-working.
I just lost a bunch of pitchers due to overfeeding or something too..oops. Don't worry - try again.