Bread-Bakers v105.n040.23

It's easy to make a proof box:  get a foam chest (cheap ones, for 
picnics); put a socket in it (cutting a hole just big enough for the 
cord), put in a 25 watt light bulb, turn on.  You'll want to measure 
the temperature the first couple of times since the size and 
thickness of the foam will be variable, and you may need a smaller or 
more powerful bulb.

Alan