For about $60 you can buy a programmable t'stat so you can reduce the time your heaters running.
Buy LuxPro ELV4 (PSPLV512) Programmable (5+2) Line Voltage Thermostat, Heat Only | LuxPro PSPLV512
I use one almost exactly like this but with cool mode to control a fan behind my wood stove once it hits 85 degrees, that way keeps the wall cooler and turns back off when the fire has died down.