The Queen has said King Charles is doing “extremely well under the circumstances” after starting treatment for cancer.
Camilla left Charles at Sandringham on Thursday to fulfil her first royal engagement since the palace announced earlier this week the King had been diagnosed with cancer.
Charles has been spending his time in Norfolk following his diagnosis, although he hosted a whirlwind visit from his son Prince Harry at Clarence House on Monday.
Greeting medical staff from Wiltshire Air Ambulance at Salisbury Cathedral, Camilla said her husband was “very touched” by all the messages of support he had received.
Paramedic Ben Abbott told her: “I do hope His Majesty is doing well, Ma’am. We’re all really sad to hear the news.”
She replied: “Well, he’s doing extremely well under the circumstances.
“He’s very touched by all the letters and the messages the public have been sending from everywhere – that’s very cheering.”
Together with the Prince of Wales, the Queen is preparing to take on more engagements since the King stepped back from appearances to undergo treatment for the disease.
He has postponed all public-facing duties, but is continuing with behind-the-scenes work on state papers.
The 75-year-old has been diagnosed with an undisclosed form of cancer following hospital treatment last week for an enlarged prostate, which is unrelated to the cancer.
He underwent his first bout of treatment for the disease earlier this week.
Camilla has a home in Lacock, also in Wiltshire, and she chatted with the air ambulance medics about their work.
Mr Abbott said: “I told her we always wave when we fly over Lacock and she said she always waves back.”
On Wednesday night, Prince William expressed his gratitude to the public for their kind messages of support.
The heir to the throne was back at work after taking time off to support his family following the Princess of Wales’s abdominal surgery.
William’s words of praise, during a gala dinner, also recognised those who sent good wishes to his wife, Kate, as she recovered from the operation. He told the guests: “It means a great deal to us all.”
The Princess of Wales is not expected to resume public duties until April.
Weekly audiences between the King and Rishi Sunak are expected to resume in person in two weeks’ time following Charles’s diagnosis, it is understood.
King Charles on Wednesday night issued a statement to mark the 50th anniversary of the independence of the former British colony Grenada, apologising for being unable to visit the Caribbean island.
He appeared in good spirits as he smiled and waved to the gathered crowds as he left London.