Electronic Alarms and Home Security Devices - temperature sensor

I already had posted this in Home Automation but I think that was the wrong place...so it is again;

I live in the upper midwest where it is close to zero degrees today. I am going to be gone for a week and seems like I have heard there was a sensor of some type that you would plug a lamp into it and if the temperature in your house would drop to low a light would go on so if you had a neighbor watching it he could take care of a problem.

Appreciate any ideas from anyone.

Thanks,

Harlan.

Try this link. There are a number of similar devices on the market. This one is designed to switch 24volt max, but could be used to trip a relay for heavier loads:

http://www.smarthome.com/7151.html

They are readily available in most hardware stores, I think even Wal-Mart has them.