A thermal fuse is a single operation device similar to a current limiting fuse which is sensitive to surrounding temperatures instead of the current passing through it. The small low current type are made using a fusible link material whereas the higher capacity fuses are equipped with an organic or wax pellet which hold the contacts together by compressing a spring. When their temperature threshold is reached the link or the organic pellet melts thus breaking the electrical circuit. Care must be taken during transportation, storage and installation that the device not be subjected to temperatures near the operating temperature. Special attention must be taken during soldering of the leads. It is also critical that the Tc (continuous temperature) not be exceeded as it could cause deterioration of the link or pellet and lead to eventual failure of the device.