If a server has become inaccessible via SSH due to high load, I would usually restart it.
How do you usually find out the cause of the high load (e.g., what process, how much RAM/CPU was used, etc.)?
I am using WHM / Cpanel.
ssh 192.168.1.1 killall -9 httpd
OR rsh 192.168.1.1 killall -9 httpd
instead of reboot,
thus you will save a time.