This is global warming, wandering polar vortexes. The problem is mainly Texas construction. Central heat and air in Texas run the ductwork thru the attic, except for 2 story houses (which usually have it between floors). Because cold air drops and air conditioning is our major issue, attic ductwork makes sense for AC.. Warm air from the furnace does not drop, the cold wind chills the attic so when I run my central heat I am blowing money thru the attic and out the vents, but the house doesn't get much warmer. So I don't use central heat. I put magnetic sign material over the vents and heat down here where I live. But since I can't stand my room hot and space heaters are a major fire hazard, i don't heat my room, with its old wiring, with a space heater. i do heat the office and back bedroom that have all new wiring.