This website seems to give fairly accurate Maximum Operating Temperatures.
For the RX 580 it shows this to be the Maximum Operating Temperature:
In the past, Users needed to configure the GPU Power settings in Radeon Settings to stabilize the RX580 GPU card from crashing.
Try using Radeon Settings Tuning and configure the GPU Power settings (50%) and see if that helps with the crashing.
The Recommended minimum PSU wattage for using a RX580 in a PC is 450 Watts.
Try running OCCT GPU, CPU and PSU Tests and see if it crashes during any of those tests. If it crashes see if it was due to Overheating, Power issue or hardware issue.