This simple project with easy to build electronic circuit is very useful to fight with problems like overheating or overcooling of electronic devices which in turn [[wysiwyg_imageupload::]]leads to their damage. This circuit automatically switches off the circuit in event of excess heating or excess cooling. With small modification it can work as both overheat circuit breaker and overcooling circuit breaker.This simple project has a circuit is based around the temperature sensor LM35, which senses the surrounding temperature and gives the corresponding voltage output at its output pin, its output voltage when multiplied by 100 gives the temperature sensed in degrees. By using this fact the reference can be set accordingly.