Thermal Insulated Blackout Curtains The purpose of insulated curtains for winter in winter is to reflect the heat generated inside the space It makes no sense to hang your curtain in front of a heater because it keeps the heat trapped between the curtain's back and the window Additionally, it is not advised to hang them in front of a radiator because the fabric has not been treated to be fire - resistant, which could be dangerous Cut it if it is getting in the way However, if you feel you must shorten the multi - layered thermal door window curtains , please cut it carefully www.thermalwindowcurtains.com +1 540 - 214 - 0678 Help@ThermalWindowCurtains.com 4445 CORPORATION LN STE 264, VIRGINIA,BEACH ,VA, 23462