We bought this for our large unfinished basement.  It helps but it doesn't make much of a dent on a cold day unless you have it on for a long period of time.  I'm sure it works fine in smaller, more enclosed spaces.  It's hot to the touch but I don't worry about it with my 21 month old toddler.  It's not *that* hot.  My husband uses it when he's downstairs doing woodworking for a long time.  I sometimes use it when the kids play in the basement.