I say, and with God's guidance: It is not obligatory, but it is recommended to perform the ghusl (ritual washing) for him; by analogy to fainting; as narrated by Muslim in his Sahih from Ubayd Allah bin Abdullah who said: "I entered upon Aisha and said to her: 'Will you not tell me about the illness of the Messenger of Allah (peace be upon him)?' She said: 'Yes, the Prophet (peace be upon him) became seriously ill and said: 'Did the people pray?' We said: 'No, they are waiting for you, O Messenger of Allah.' He said: 'Put water for me in the basin.' So we did, and he performed ghusl, then he went to lean but fainted, then he regained consciousness and said: 'Did the people pray?' We said: 'No, they are waiting for you, O Messenger of Allah.' He said: 'Put water for me in the basin.' So we did, and he performed ghusl ...', and Allah knows best.