May a sick man stay in his ex-wife's house when his children want to care for him there?

Summary

A former husband and wife whose waiting period has ended are legally strangers, so they may not live alone together in one house because it may lead to seclusion and temptation. However, he may stay there if a mahram of either party, such as their children, or a trustworthy woman is present. It is also permitted if the house is large with separate rooms, cooking and resting areas and no passage that brings them together. Both must observe Islamic limits, such as covering the aurat and avoiding lengthy conversation without need.

Written in our own words from the original fatwa — check the source before acting on it.