Well.. it quickly manifests physically in addition to mental stress.. Like you can imagine the guys forced to spend 30 days on an oil platform get 5 figure salary, no internet. When you hit day 14, you will start to go insane. And on oil rig, all batangs some more. Not easy to tahan. Even you will start to hate the food (and based on reliable info, it is actually good food by our standards - but also depends  on who owns the rig hahaa.. also got 3-5 star rig reputation one lol).