The medical series Holby City began in January 1999 as a spin-off from Casualty and is named after the fictional Holby City Hospital in which it is set. The show follows the lives and careers of staff and patients at the hospital and also deals with a range of clinical and ethical issues. The regular characters are all staff, and patients are often played by guest actors.

(Source: Wikipedia)

EPISODE SYNOPSIS
Ric rushes back from a conference and straight into a crisis, as the medical drama continues.
The new, improved Keller ward is about to open and Ric wants to make sure everything goes smoothly. However, when he gets back to the hospital, he realises that Diane is struggling to cope. The thermostat is broken and the temperature in the ward is hovering around 90˚C. Ric is forced to take charge of the situation and go ahead with his surgery schedule against all odds.
Elsewhere, Diane and Chrissie nearly come to blows over Owen in front of patient Clayton Jones (Philip Quast), an Aussie pilot who is diagnosed with a rather serious heart condition. At first he seems to be more interested in flirting with the nurses than in his own health situation, but his state suddenly becomes life-threatening...

(Main source: Holby.tv)

PHILIP QUAST as Clayton Jones - from Sue H. (Spoilers!)
Clayton Jones is an airline pilot, who is really a cheeky character, charming all the nurses. Clayton Jones has been admitted to hospital because of pain in his chest, tests have revealed that only one of the four chambers of his heart are working. Whilst nurses are doing regular checks, he complains of pain in his leg, which means he has to be rushed into surgery; when he hears this, he gets very frightened, but one of the nurses reassures him that everything will be alright. We next see him in theatre, fast asleep with that white streak of hair really showing up, his leg opened up, whilst operating he has a massive bled, but through the skill of the doctors, comes through the surgery.
His character changes when we next see him, as he comes to realise that his life is going to have to change.