The health challenge left in the wake of Typhoon Haiyan is vast and daunting.
As well as clearing dead bodies and responding to the immediate injuries and trauma, there are many "regular" health needs to be met.
It's expected that 12,000 babies will be born this month in the affected areas.
People with illnesses such as diabetes or heart disease will need to get their regular medication, even though many transport routes have been destroyed.
With tens of thousands of people now homeless, there is mounting concern that crowded living conditions and contaminated drinking water could lead to outbreaks of infectious diseases.
The peak danger period for this is between 10 days and one month after the event, according to the World Health Organization.
Unsafe food and a lack of access to safe water, lack of facilities for personal hygiene and safe sanitation arrangements all create a breading ground for infections, such as cholera.
With another tropical storm expected to hit the Philippines later this week, the need for shelter, safe water and sanitation is critical.
WHO is working with other humanitarian organisations to secure urgently needed water purification tablets.
Special diarrhoeal disease kits with medicines and supplies to treat 3,000 cases of acute diarrhoea are also en route - contaminated water is a frequent cause of diarrhoea.
Medicines and supplies to cover the basic health needs of 120,000 people for a month have been deployed.
And work has begun to strengthen an early warning system that can rapidly detect disease outbreaks and other public health threats.
WHO says the next steps will be critical.
It is how the survivors, rather than the dead, are managed that determines if and when an epidemic may occur. There has never been a documented case of an epidemic occurring after a natural disaster that could be traced to exposure to dead bodies.
Providing the most basic of needs - safe food, clean water, medicine and shelter - is what will make the difference now.