What should a person do when they are first injured at work?

I've discussed this issue before as it is important to your rights in workers' compensation.  The most important thing is to report your injury PROMPTLY to your employer; provide the date and  physical location where the injury incurred.  If you do not inform your employer, no compensation is given until proper notice is provided.  Notice must be given no later than 120 days after the injury in order to be eligible for compensation.  You have three years  from the date of injury to  file a claim petition.