William, a former search and rescue helicopter pilot, told emergency workers on a video call that they must not be afraid to ask for help despite their inclination to help others first. 

"I fear…you're all so busy caring for everyone else that you won't take enough time to care for yourselves, and we won't see the impact for quite some time,'' William, the second in line to the British throne, said on a tape released late Friday. 

Britain's health care system is staggering as a more contagious variant of the coronavirus coupled with cold, wet winter weather puts an unprecedented strain on hospitals and emergency workers. 

The London Ambulance Service says it is receiving about 8,000 emergency calls a day, compared with 5,500 on a typical busy day. But the strain is being felt across all emergency services. Hundreds of firefighters, for example, have volunteered to drive ambulances to ease pressure on beleaguered services. 

The surge in infections across the U.K. has pushed the number of people hospitalized with COVID-19 to a record 37,282, more than 70% higher than during the first peek of the pandemic in April. Britain has reported 87,448 coronavirus-related deaths, more than any other country in Europe and the fifth-highest number worldwide. 

Eleven months into the pandemic, the pace is taking a toll on the men and women who are first to respond to calls for help. 

But many emergency workers aren't taking advantage of counselling and other support programs because they are too focused on responding to the crisis, said Phil Spencer, a police inspector who coordinates well-being programs for the Cleveland Police force in northeastern England. 

"Perhaps further down the line, when all this is gone, we're going to have some broken police officers and emergency services staff, because we're too busy focusing on protecting the most vulnerable," Spencer told the prince and his wife Catherine, the Duchess of Cambridge. 

William and Kate have made ending the stigma attached to mental health issues a focus of their charitable work. 

As the couple chatted with emergency workers and counsellors, William shared his own experiences of working as a helicopter pilot for the East Anglian Air Ambulance. 

"I think a lot of the public don't understand that when you're surrounded by that level of intense trauma and sadness and bereavement, it really does, it stays with you at home, it stays with you for weeks on end, doesn't it?'' he said. "And you see the world in a much more, slightly depressed, darker, blacker place."