William gave a speech to 200 front line heroes opening up about his time in the emergency services.
He said: “I often think about my time working for RAF Search and Rescue and the East Anglia Air Ambulance.
“I remember the pressure of attending calls in the most stressful conditions, sometimes with tragic conclusions.
“I remember the sense of solidarity with my team, pulling together to do the best we could and sharing the weight of responsibility.
“I also remember returning home with the stresses and strains of the day weighing on my mind, and wanting to avoid burdening my family with what I had seen.”
He described the “complexities of talking to family and friends about the job” and “having a split personality – one for home and one for work”.
Prince William said mental health support for emergency workers must be “prioritised”.
Speaking directly to the frontline heroes sitting in front of him, he added: “The work you do is some of the toughest out there, and we owe you an enormous debt of gratitude.
“I would only ask that you look out for your own wellbeing, just as you tirelessly care for everyone else’s.”
The Duke later spoke to Met Police chief Cressida Dick, MP Sajid Javid and event host and compere Nick Knowles.
He also met some of the emergency responder heroes including Dr John Chatterjee, of London Air Ambulance.
Dr Chatterjee said afterwards: “He said he misses the uniform and I think it’s that rush you have in all of us in the job a balancing act between being serious, exciting and rewarding and that’s the thing that people miss when they leave the service and retire.”
On stage during the two-hour Emergency Services Mental Health Symposium, Met Police Commissioner Cressida Dick hailed William’s “passion” and “sheer hard work” on mental health support for frontline workers.
She said: “You have always been a stalwart supporter of our emergency services and as a member of our emergency services.
“We are deeply grateful for your work and that the Foundation has been doing in the last few years in relation to mental health. It has made a huge difference.”
She said Met Police lost 70,000 working days last year due to mental health issues and 70 per cent of all frontline workers have said their mental well-being deteriorated since the pandemic.
She said “they are not superhuman” and will help “drive well-being”.