The PC is unknown so if it's the usual desktop, remove the cover and point a fan at it to see if it gets better or takes longer to do that.
While I've worked such many times at the office I usually get at least the make, model, age, story about maintenance and more. Here you wrote very little.
My PC has been gradually getting more issues over the years with my FPS on games like CSGO going from 150 to 30fps for around 20 seconds before returning back to 150, now though it's began just randomly switching off. Sometimes after 5 minutes and sometimes after 20 hours. Anyone have any ideas on the issue?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic