He has come close to death in war zones and witnessed abject horror on several occasions. And while he described the "most incredible adrenaline buzz" of the proximity to (his own) death in warzones and working in an austere environment to save the life of others as close to euphoric, his intense experiences led to him suffering severe, "almost psychotic" post-traumatic stress disorder.
Nott has been given an OBE (an Order of the British Empire medal) for his work and in 2014 he was invited for lunch with the Queen in Buckingham Palace, just 10 days after returning from one of his missions.
He described sitting at the table next to the Queen, but struggling to find the words to start up a conversation.
The Queen said: "I heard you have just come back from Aleppo," to which Nott responded: "Yes I have."
Nott said: "If you consider where I had just come from, the hospital was being blown, everything around me was being shelled, and I was coping with children who had been really badly damaged. And she must have detected something significant, because I didn't know what to say to her. It wasn't that I didn't want to speak to her, I just couldn't. I could not say anything."
"Why don't we feed the dogs?"Then, Nott said, the Queen did something incredibly touching.
The Queen asked Nott: "Shall I help you?"
Nott had no idea what to say: The Queen? Helping him?
But then, Nott said, the courtiers brought in the Palace's Corgi dogs, who went under the table.
Queen Elizabeth II laughs as she watches the racing at Epsom Racecourse on June 4, 2016 in Epsom, England.
The Queen asked one of the courtiers to open up a box of dog biscuits.She broke a biscuit in two, handed one to Nott, and said: "OK, why don't we feed the dogs?"
"So for 20 minutes, the Queen and I, during this lunch, just fed the dogs," Nott said. "And she did it because she knew that I was so seriously traumatized. The humanity of what she was doing was unbelievable."
"Desert Island Discs" presenter Kirsty Young then asked Nott whether it helped.
"Very much so, I think stroking animals, touching dogs, feeding them — we just talked about her dogs and how many she had, and she was so warm and so wonderful, and I'll never forget it," Nott replied.
"Desert Island Discs" is a long-running radio show in which guests are interviewed about their lives and asked to select the eight records, one book, and one luxury item they would take with them to a desert island.
Myfanwy — The Treorchy Male Choir and The Jonathan Price String Ensemble
Gadael — Triban
Stairway to Heaven — Led Zeppelin
Cavatina — from The Deer Hunter theme
Gimme Shelter — The Rolling Stones
Fix You — Coldplay
Clair De Lune — Claude Debussy
Good Golly Miss Molly — Little Richard
Book choice: Kallimni 'Arabi Mazboot by Saimia Louis
Luxury item: Fishing rod