Based at the Chelsea and Westminster, St Mary’s and Royal Marsden hospitals in London, for the past 20 years David Nott has also volunteered for the Red Cross, travelling to war zones including Bosnia, Iraq and now Gaza.

Here he describes last Friday – meant to be the first day of a ceasefire – and why he risks his life to help the wounded in ‘Apocalypse’ Gaza.

Last Friday was supposed to be the start of a 72-hour ceasefire, but within two hours, all hell had broken loose.

In the end I spent almost 12 of those hours in the operating theatre at Gaza City’s Al-Shifa Hospital, where I’m based. It was a difficult day.

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Front line: David Nott, in the foreground, operates on a 25-year-old man on Friday. The patient died in intensive care six hours after surgery

We had a child, an eight-year-old girl, who had severe fragment wounds from an exploded bomb. She had a hole in her stomach, her back, in her chest and colon.

Thankfully, we did manage to save her.

Most of the operations we’re doing are on children and young people. They come in with crush injuries, and massive fragment wounds from shells and bits of buildings.

In the afternoon, we heard that the hospital was about to be bombed. I was operating at the time so could not leave the patient. There was only me and a colleague.

We are both very experienced, so we hid ourselves away in the operating theatre and just went on with it.

On Friday night I was operating on a 25-year-old man who had massive injuries caused by a bomb blast. Sadly he died in intensive care six hours after surgery. The trauma was just too much for him.

Exhausted medics take a break as relatives desperate for news wait outside

We don’t know where the bomb threats come from.

The situation is unfathomable, to be honest. There are other groups fighting apart from the Israeli Defence Forces and Hamas, so the threat could have been from anybody.

We’re aware all the time of the bombs: there’s the constant ‘thud, thud, thud’ of them. But we operate all day, trying to save lives and limbs.

In a sense it’s easier being the surgeon, because you are just stuck in the operating theatre.

It’s far more difficult for my Italian colleague, Dr Mauro Della Torre, who’s working in the emergency room receiving everybody who comes in.

A couple of days ago, 140 people came in, in 20 minutes. He was on the floor doing operations, performing tracheostomies.

He says the Al-Shifa’s ER is ‘the most chaotic in the world, but it’s still functional’.

A few days before that we had all seven operating theatres going as well as procedures on trolleys outside, such as on a man whose arm and shoulder had been blown off.

But no matter how bad it gets, everybody gets a chance of life here. Nobody is turned down for treatment, apart from those who have absolutely no chance of surviving.

Last week was like the Apocalypse. It was night and there were rockets coming in from the sea, fire from tanks and F-16s dropping bombs everywhere.

It was indescribable, as if we were in one of those silly Tom Cruise Hollywood movies.

None of us could sleep because the bed, the room, even the house was shaking.

It was like the end of days. You feel your life is in danger. I could have died that night.

During a ceasefire last week the Palestinian Red Crescent Society brought in 100 bodies, which they had not been able to get to before because it was so unsafe.

Some of them had been dead for eight days. The smell hung around for days.

Terror: A Palestinian paramedic carries an injured child into Gaza's Al-Shifa Hospital after an Israeli strike

Will this make me stop? No, far from it. The trouble is there might be another Apocalypse tomorrow.

Why do I do it? Because I feel that I can offer help and support in desperate situations.

But to do this job you have to detach yourself completely from what is going on around you. Because if you don’t, you won’t be able to work and do your best for the patient.

That takes experience. It might sound odd, but what I do here is comparable to my NHS work. Every case is the same, in that you are trying to do the best you can for the patient.

It is different surgery, but the mindset is the same.

Some say I must find it terrible. But it is not because you are doing what is right for the injured.

Calling: Surgeon David Nott has volunteered for the Red Cross for the past 20 years travelling to war zones around the world

Obviously in the NHS, working in London or wherever, it’s quiet and calm. Here at any moment you could die. But that is the risk that you take if you feel you have a calling, as I do.

I don’t have a wife or children, or parents to worry about me. I could have chosen marriage but I didn’t want it. I wanted to do this.

There have been some terrible things that have happened since I have been here.

Last week there was a six-year-old boy wandering in the street, with either autism or post-traumatic stress disorder, and he was screaming. It sounds awful, but somebody had tied him to a tree.

The International Committee of the Red Cross talked to the combatants, and it was arranged for an ambulance crew from the Palestinian Red Crescent Society to go to rescue him.

But when they went to save the child the crew was attacked and the driver shot dead.

Another time I was at a hospital dealing with 180 casualties who came in. A Palestinian doctor there was in tears, sobbing uncontrollably.

He told me he had been called over from another hospital in the middle of the night because of an attack.

One of the casualties was a girl, about 19 or 20, who had lost her baby and sister.

This surgeon amputated her right leg, performed a vascular bypass graft, shortened her femur, and fixed up her abdomen. He was crying because she was his sister.

There is terrible human suffering here. It needs to stop.