How Much Stress Is Too Much Stress?

Stress seems to be very commonplace a problem these days. Most people I know complain about it: it's stressful to work, there's no time for hobbies, houses must be built, homes must be tidy, there's never time for anything (except for maybe watching telly). The expectations are simply higher than what one is able to do. Sometimes one's financial situation causes a great deal of stress.

Time management, attitudes and priorities aside, there's one thing I've been thinking about. There are people who are so wrapped in their own stress and negative emotions that they don't seem to function properly. Suddenly everything is too much for them. The problem is that others cannot turn to these people for advice or help: their stress shines through and affects others negatively. Their own pain prevents them from seeing and sensing how others are feeling. What do you do when you have a person like this in your life, someone who seems to be ready to explode any minute? Do you try to listen and help them work it out? Do you suggest they get help (with the risk of being yelled at)? Do you just run? Telling them about time management, attitude change and priorities does not seem plausible, since they might actually bite your head off.