The harchakot are the activities from which husband and wife refrain while the woman is nidda.

What happens when, chas veshalom, one spouse is ill? How can the other spouse help if touching, and even passing objects, is prohibited?

The Shulchan Aruch distinguishes two cases

We see in the Shulchan Aruch a difference between a sick husband and a sick wife.

If the husband is ill and only his wife is available to help him, she may do so when necessary. However, they must avoid touch whenever possible. When touch is necessary — helping him to sit up or get into bed — it should be done through a barrier if possible, such as gloves or a blanket.

If the wife is ill, serious effort should be made to locate an alternative caregiver. If that is impossible and the husband is the only option, he may help his wife in the manner described above.

This distinction rests on the assumption that while an ill husband will not have the strength to encourage his wife toward forbidden behavior, an ill wife could be swayed toward forbidden behavior with the healthy husband.

Plan ahead where you can

If a couple knows ahead of time that they will be in this situation — before a scheduled surgery, for instance — I would encourage them to be in contact with their rav or yoetzet halacha to discuss practical solutions for their specific circumstances.

Source expansion

The Rosh notes that a wife may take care of her sick husband but must do her utmost to avoid making his bed in his presence, washing him, and pouring him wine in his presence.

Terumat HaDeshen discusses a situation where the husband is a doctor and his wife needs her pulse measured.

The Ramban rules that this is forbidden.

The Beit Yosef understands that the Ramban would permit it in a situation of pikuach nefesh. But he holds that the Rambam would nevertheless forbid it, because the Rambam holds that affectionate touch with a niddah, or with any of the arayot, is within the category of yehareg v'al ya'avor.

Shulchan Aruch: a woman may care for her sick husband, but she must be careful to avoid washing him, pouring wine in his presence, and making his bed in his presence. If the wife is ill and a niddah, her husband may not touch her to aid her.

Rema: if she has no one to help her, the husband may help his sick wife when she truly needs his help.

Shach: even the Rambam would permit helping her in a situation of pikuach nefesh, because the Torah prohibition on touch applies only when the touch is affectionate.

Practically speaking, Ashkenazim rely on the Rema. Sephardim also rely on the Rema, following the ruling of Chacham Ovadia zt"l.