Specialist maxillofacial surgeons Tim Martin and Sat Parmar prepare for a marathon operation on 53-year-old Teresa. Four weeks ago, Teresa was diagnosed with a fast-growing cancerous tumour in her face and she will die within weeks unless it is removed.

The surgeons take on unpredictable, high risk operations. They need to stop a patient's heart, chill his body and drain out all his blood before they can operate to save his life.