Could be Thermostat but more likely The Compressor Start/Relay.
Did you hear anything before this like the Motor Buzzing and Stopping.
What ever I would advice getting in a Frig man to take a look. Not the job for a DIY.
TOKES
October 2010
Automatic Answer
While you wait for answers, we may have found some information which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix freezers.