Some info on small area heaters…from Consumers Report
"We Tested four personal heaters that can be placed under a desk or workbench to boost the heat in a confined space, such as your cubicle at work. Though most of the regular heaters in our tests have an output of 1.500 watts, the output of these pint-sized space heaters ranges from 200 to 900 watts, so they cost less to run.
Tops in the batch is the 3-pound Vornado SRTH, $45, with an output of 900 watts. It is good at spot heating, stays cool to the touch, and is relatively quiet. The Bionaire BCH4562E, $40 isn’t quite as good at heating, but it’s super-quiet and has a motion sensor that shuts off the heater if no movement is detected within 2 hours.
We also tested the Honeywell HCE100B, $25, and the Lasko My Heat 100, $20. They don’t perform as well, but with outputs of 250 and 200 watts, respectively, they don’t cost as much to operate–$10 per season compared with $50 for the Vornado."