This morning upon entering the office, I watched a co-worker of mine enter and head up to his desk.
Shortly after a security guard entered and asked about the alarm going off.
On my way upstairs I passed this co-worker and then asked if he had let in the security guard in to the building, I was answered by <expletive deleted>. This comment was made in a threatening manner at the top of his voice. I asked what that was about and I then received some rambling incoherent thoughts about my talking to another staff member about him.
What should I do about this, he is clearly a very unstable man and lashes out on many other staff members.
He has many personal problems even so I still think that it is completely inappropriate behaviour to tell another co-worker to <expletive deleted>.
Please help, any comments would be welcome.