I have a question about 1 Kings 1:2. The aging king David is too cold, and the solution to keep warm is to have a concubine/nurse lie down with him. They found Abishag, a very beautiful virgin, but of course the scripture was clear that no sexual relations were involved. The advisers were obviously more concerned about David's health than whether David became impure in his thought. I know of an old brother with prostate problems who needs a companion. This kind of practical solution could help him emotionally -- but not everyone can accept it, especially my church leaders.
Nor do I think they should. David was a king, drawing near the end of life, and this young woman (presumably) was regarded as one of his wives. In the ancient Near East, virility appears to have been a test of one's fitness to reign. If the king did not have relations with even a beautiful girl, then he would be deemed unfit to reign. Yet the older brother you mention is nowhere close to being in this situation.
Moreover, polygamy is almost certainly illegal in your country. Secondly, nothing in the text suggests that an older man would not feel tempted if a beautiful woman were in his bed! But in David's case, since Abishag was his concubine (or secondary wife), whether there was sexual contact or not is in a sense irrelevant. Not so with the older brother you know! I see no reason why he can't just add an extra blanket (perhaps an electric one?) or, if he is in better health, exercise more and increase his metabolism.