Trap Generator set to "temp-exception"

Anybody can tell me what the Trap Generators “temp-exception” means? It seem to be set by default.
What is it doing? Or avoiding to do?

if the device gets to hot, it wil start sending snmp traps …

really, means in default no SNMP information is available as long as the temperature is low?
That does not match my experience.
Should be

start-trap - SNMP server starting on the router

the default?