Can a person with Hepatitis B, high blood pressure, and diabetes do heavy chores?

I know someone who has all of those conditions, but he takes medicine and shots for the diabetes and high blood pressure. He HAD Hepatitis B two years ago, and he's fine now. Can he do heavy chores like mow the lawn? It's got a somewhat steep slope, so you'd have to pull the lawn mower back. Anyways, he wouldn't have to do it often... just once a week during summer. Is this okay?