VICTIMS of explosions involving gas or fuels are initially more likely to die from inhaling smoke and hot fumes than from their burns, according to a leading surgeon. Professor Arthur Li Kwok-cheung, dean of the faculty of medicine at the Chinese University, said: ''The main danger is not so much the heat generated, which burns the skin and clothes, but inhalation of smoke. That is what kills the individual.'' However, even if patients survived the initial inhalation of smoke, they were still in danger of dying of lung damage caused by breathing the hot fumes. Professor Li, also chairman of surgery at the Prince of Wales Hospital, said the body reacted to damaged tissue by swelling and leaking body fluids. When the damaged tissue was in the lungs, ''they could actually die of drowning through water clogging the lungs'', he said. If the patient survived this stage, he was then at risk through his burn injuries - ''the actual loss of skin and the loss of fluid''. Professor Li said one of the problems with burns victims was the body leaked water plasma - that is, protein-rich water. This led to cardiovascular instability because there was not enough liquid in the body. At this point, burns victims could die of heart failure if the fluids were not replaced rapidly. Finally, having survived the more critical stages, burns victims were still vulnerable to infection due to the loss of the protective skin covering. ''If you don't have the skin to keep them out, even simple germs could be nasty to you,'' he said. Professor Li said when it came to analysing how severely burned a patient was, doctors divided the body into 11 parts, each with a value of nine per cent. Each arm, for example, was worth nine per cent. Patients with moderate burns covering 10 per cent of the body's surface had to be admitted to hospital, as did those with burns to certain areas such as the hands. Burns of 15-25 per cent were considered severe, he said. Professor Li said the most important treatment of burns victims was initially basic resuscitation, which most medical centres, including those in China, should be able to provide. Later on, however, they would need specialist treatment such as reconstructive plastic surgery. He said the Prince of Wales Hospital was treating two children from China who had been badly burned and whose faces needed extensive reconstruction. He said the hospital had a disaster contingency plan to deal with huge accidents but had never been required to activate it. A Hospital Authority spokesman said Shenzhen authorities had not asked for help from Hong Kong in treating the burns victims.