Charles has cancer: what if the king can't?. The distribution of tasks is clearly regulated even in the event of the king becoming ill.
If the king is ill or is abroad, he can delegate some tasks to “Counselors of State” – i.e. state councilors. Traditionally, these are the monarch's wife, Queen Camilla, as well as the first four people in line to the throne who are over 21 years old. For now, the Windsors are looking for normality – as much as possible.