Kerry as just set up the bigger Viv and is using a CHE for heat the smaller viv kept pretty hot so she turned the CHE off on a night and turned on the heat mat, but this Viv is alot bigger so it is going to need the CHE all night. I know there is a Thermostat you can use that controls the CHE and turns it off when it is too hot the on again, but we are not sure were to get one, we live in the Uk so do not have Walmart could someone tell me a name of a good Thermo that we can use and were we would get this, i am really nervous about the CHE being on all night but dare not turn it off because the mat will not keep the Viv warm enough for the RF,