When faced with a life-threatening illness or injury, humans all share one overwhelming instinct: to fight for life.

Episode two of Fight For Life continues its celebration of the human body with a look at childhood and how it joins forces with modern medicine to overcome trauma and illness.

Before a child has had time to fully develop, they are particularly at risk from deadly diseases, as well as accidents. But children’s bodies also have unique strengths that can help carry them back from the brink of death.

This series shows the power and emotion of each patient’s story from the outside, and uses advanced CGI to explore what’s going on inside the body.

Nine-year-old James’s heart is so malformed it could collapse at any time. To save him, he must endure one of the most severe traumas a body can face – a heart transplant. As his new heart begins its long journey from the donor to the operating theatre – kept alive in ice – James must be prepared in theatre in time for its arrival.

The programme follows his incredible struggle for survival, from the operating table to his fight against a dangerous fungus which takes hold of his body after the transplant, leaving him with only a 70 per cent chance of survival.

Another patient, nine-year-old Arun, is rushed to hospital when he suffers a terrible asthma attack. He is terrified and struggling for every breath and, together, the medical team and Arun’s own developing immune system fight to bring his attack under control. This episode reveals the battle both from inside Arun’s lungs and from the medical team’s viewpoint on the outside.

Finally, every parent’s nightmare is explored as Fight For Life shows how two-year-old Gabriel’s defences are challenged by a fall under a train.

Monday 16 July
9.00-10.00pm BBC ONE