I bought a kennel heating pad ,when our female was fixing to have a litter.
planning on bringing it out again, now that they are getting on in years,has a thermostat ,and wire guard,fleece cover.
works so good,they wont sleep on it,just on the edge of it. laugh
just have to turn down the thermostat some more.
IIRC,it was about 100 degrees warm just plugged in, without the external thermostat

https://www.amazon.com/Manufacturin...p;ie=UTF8&qid=1481282211&sr=1-10

Last edited by fluffy; 12/08/16.
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[the member formerly known as fluffy}