I'm not taking about plugging another extension cord in the wall. You'll still only have the one extension cord plugged into the wall. I'm saying use one of those small extension cords with multiple plugs on one end. Plug both your CHE'S into that cord, and then plug that cord into into the Thermostat, then plug the thermostat into the original extension cord plugged into the wall. Your basically just running 2 heat sources off one thermostat. You wouldn't have to buy another one.i already have an extension lead as we dont have a socket near his pen. id worry about adding another ext lead, due to fire risk, but thank you for the tip