Earlier this week, we reported that Prince Philip, 99, had been hospitalized after he told doctors that he was not feeling well. Now, his son Prince Charles, 72, has paid him a visit at the King Edward VII hospital in London.

Entertainment Tonight reported that Buckingham Palace released a statement saying that Philip was only hospitalized as “a precautionary measure,” and that his illness is not related to COVID-19. A source said on Friday that Philip will likely “remain in hospital for observation and rest over the weekend and into next week.”

“The doctor is acting with an abundance of caution. The Duke remains in good spirits,” the source said.

Charles, who is the heir to the throne, reportedly just paid Philip a visit in the hospital.

Royal biographer Penny Junor said jokingly that doctors and nurses at the hospital “would not want” Philip on their shift since he gets “irritated” by people fussing over him.

“I think he (Prince Philip) can be quite blunt and I think if he felt people were fussing over him he could be quite outspoken about that,” Junor said. “This is a man who doesn’t want any fuss made of his 100th birthday, so the fact he’s in hospital and getting some fuss made of him will really irritate him.”

Royal sources said that the husband of Queen Elizabeth had been “sprightly” and was seen “in very good humor” before his admission. He is reportedly in “good spirits” and is staying in a private wing at the hospital, which he walked into unassisted on Tuesday.

Philip has the support of British Prime Minister Boris Johnson, who released a statement saying, “The Prime Minister sends his best wishes to the Duke of Edinburgh as he undergoes a few days of rest in hospital.”

Meanwhile, the 94 year-old Queen has been continuing her royal duties at Windsor Castle. Yesterday, she spoke on the phone with the First Sea Lord, Admiral Tony Radakin, about the work of the Royal Navy.

Philip and the Queen each received their coronavirus vaccines last month, which is something they went public about in the hopes of encouraging others to get the vaccine as well. Philip is preparing to celebrate his 100th birthday in June, and since he retired from royal duties in 2017, he has stayed busy. with reading, writing and painting.