You can talk to him about this matter. You can ask him to stay in a different house. You have to tell him that these things are not only affecting his physical health but also his mental health. And it will continue to affect him if he doesn’t take any action.
He can also file a complaint against her under Section 506 of IPC, 1860: Punishment for Criminal Intimidation The husband can file a case against his wife, claiming that she threatens him to hurt himself or his family or property. Yet again, the evidence is the only thing that can uphold his case.
Therefore, you have to tell him to gather evidence as much as possible. So that, it would be easy to file a complaint.