Check your GPU heat, pushing ctrl+shift+esc will bring up task manager. Click on the performance tab, your GPU will be displayed with its temperature underneath it. Anything too hot will cause crashing, this can be remedied by taking off the side panel and getting your machine a big ol’ external fan, or leaving your PC to cool off for a while. This can be caused by the weather, environmental factors or hardware failure like fans not working, or dust buildup.