Within hours of opening a tent hospital amid the devastation of Typhoon Haiyan, Australian doctors had saved the lives of three people, one of them a five-year-old girl with a fractured skull.
Mark Little, one of 14 doctors working at the hospital, said the girl was out of bed and eating within hours of surgery but probably would have died without it.
''We hope there will be many more lives saved in the coming weeks,'' Dr Little said.
A 60-year-old man's infected leg was amputated as staff from the Australian Medical Assistance Team were still erecting tents on a concrete slab a few hundred metres from Tacloban airport, where cargo planes are flying in tonnes of desperately needed relief aid and thousands of displaced people are being evacuated.
Doctors, working at the hospital in extreme tropical heat and often torrential rain, can treat up to 200 patients a day and have a fully equipped operating theatre, with sterilisation and X-ray units.
The unit, based in Darwin, was set up after the Bali bombings to provide an emergency response to disasters in Asia and Australia. With 40 staff members it is completely self-contained with its own water purification system and accommodation.
Bill Tweddell, Australia's ambassador in Manila, visited the hospital on Sunday after travelling to Tacloban in an Australian air force C-130 cargo plane that is running a supply shuttle between Tacloban and Cebu, the regional hub for the central Philippines.
''This isn't a race but we are long-standing partners with the Philippines and wanted to be out of the box quickly,'' he said.
Australia's response has been among the largest behind the US, with Canberra sending three planes, a navy ship and pledging $30 million in aid.
An Australian C-130 is also running a supply shuttle to Guiuan, a town on the coast of Samar where all the buildings were destroyed.
The scale of the disaster has overwhelmed Philippine government agencies. Officials have dramatically increased estimates of the damage, as relief efforts reach more remote parts of the country.
As President Benigno Aquino began his second tour of the region on Sunday, the government announced that more than 3.9 million people had been displaced, twice the number published the morning before.
The estimate of houses damaged by the storm also almost doubled to half a million and the United Nations' estimate of the death toll climbed to 4460. The storm left 12,544 people injured and 1186 missing, according to a bulletin from the National Disaster Risk Reduction and Management Council.
Mr Aquino, who has been criticised for his handling of the disaster, arrived in Guiuan to review aid efforts and meet victims. He is also visiting Tacloban, which bore the brunt of the storm.
Health authorities fear outbreaks of diseases and illnesses.
Starving people in some areas are reported to be eating animals that were killed in the storm.
In Tacloban bodies have been collected and pockets of the city are beginning to come alive with some shops selling rice. Looting has largely been stopped by patrolling police and soldiers.
How to help