Physical Danger
In most cases, a rehabilitation counselor job seems like a pretty low-risk proposition. You spend much of your time on the phone, meeting with clients or employers, and typing reports.
Of course, you might work in an office that hasn't made it to the digital age. You've got client folders piled so high on your desk you can barely see the ceiling. If someone accidentally knocks into the pile while they're trying to maneuver through your tiny office, you'll be buried by the cascading pile of paperwork that threatens to crush you in an instant. If that doesn't do it, you could get carpal tunnel syndrome, or perhaps a neck ailment, from cradling the phone on your shoulder all day.
In all seriousness, though, you could run into a few problems if you're not careful. If you're working in a prison or other correctional facility, you've got to keep your wits about you. You could wreck the car, and contract a case of whiplash as you fight for a parking space while visiting a client's employer. You could even max out on the lattes while you're conducting a meeting marathon at a local coffee bar. Wonder if overdosing on caffeine is covered under Workman's Comp?