Fitted Electric Blanket – King Single These Jason Commercial luxury fully fitted electric blankets feature a 3 – heat setting user friendly controller and a fully fitted skirt to suit all mattress depths. Jason Electrics blankets are modern electric blankets with safety overheat protection. You can use the electric blanket under or over your mattress protector, depending on your preference for direct or indirect heat. Breathability of your mattress protector is also important. If the heat is trapped and cannot move through the mattress protector, it will trigger the safety overheat and the blanket will turn off. The machine washable blanket detaches from the controllers, so you can wash the electric blankets in the washing machine.