The plastic casing that the heater is built with emits a toxic smell. I put it outdoors for a couple of days and that smell did not fade.  Having that smell activated by heat and indoors cannot possibly be healthy. 
Also - BEWARE OF THE "FREE SHIPPING" promoted here by Wayfair!  It turns out that there is a $12.95 charge to return an item, even when it is defective like this one was.