My husband got hurt at work, reported it and got fired 3 days later without being sent to a doctor

My husband worked nights shift. He fell and hurt his back and leg. He reported it to his boss who told him he would have to file a report in the AM because the HR office was closed. Three days later my husband got fired for "poor performance" and he was never allowed to go to a workman's comp doctor. When he went in to get his last check he asked if he could see the workers comp doctor. His boss was there and said he remembered my husband reporting the accident. The HR people said they would "call him and tell him when to go to the doctor." What should he do in this case? We want to make sure his injury is taken care of.