problem with hashcat windows restart or switch off

[razgrad]

I have a rig with 3 x 1080 and
when i start hashcat... few minutes later come this message :

Driver temperature threshold met on GPU #4. Expect reduced performance.

windows shut down or restart
what is the problem ?

I use a asus mainbaord bequiet 600 & 500 watt, 4 gb ram
3 x 1080 geforce , driver sucessfull installed...

thank you