Device #0 is running too hot

[PirateXGG]

Hello
After time of mining with NiceHashQuickMiner
my hashrate down from 43 to 12 and i receive this message
[17:25:46][0x00003bb0][warning] core | Device #0 GPU temp: 55 C
[17:25:46][0x00003bb0][warning] core | Device #0 GDDR6X temp: 68 C
[17:25:46][0x00003bb0][warning] core | Device #0 HotSpot temp: 68 C

the tempter for me it's never get above 56 for gpu and 70 for vram
and the only way to fix this it's to restart the PC and start again
so what i have to do to fix this issue
i didn't OC my GPU
i just use the optimize option in the rig management .

[nicehashdev]

You have set your GPU to have low temperature limits (most likely through MSI Afterburner). You need to raise them back to original values.

[PirateXGG]

i never changed anything in my GPU settings also
the GPU always run at 55C-58C normally
but after 10 or 15 hours at the same temperature it's says Warning & Hot Etc....