The hazard
Everyone brings their life to work: money worries, family problems, long hours, time away from home, grief or a layoff. Stress, burnout, anxiety, depression and substance use are health problems, not weakness, and people do get better with help. They also pull your focus off the task, and on a jobsite a lost focus can get someone hurt. Looking out for each other's minds is part of looking out for each other's safety.
The action
Leaders set the tone: talk about stress openly, and never joke about someone getting help. If a coworker opens up to you, keep it between you, unless someone's safety is at risk. OSHA's recordkeeping rule treats mental illnesses as privacy concern cases, so the employer may not enter the worker's name on the OSHA 300 Log (29 CFR 1904.29(b)(6)). (29 CFR 1904.29(b)(7)(iii))
ASK THE CREW
What changes in a coworker would make you stop and ask if they are okay?
From the talk: Mental health at work. Read it in full, free, with the questions and the sign-in sheet.