I wasn't able to use until some time after the return date expired as the cold weather did not set in until mid-December.  It EMITS NO HEAT!  I sat about a foot away from it in 22 degree weather and felt no heat whatsoever from it.  All the heat from the unit simply goes up in the air, wasted.  I suspect it would be best in an enclosed space such as an outdoor, open-sided tent or a patio with a roof.