Why the first 72 hours are so important?

More than 90 percent of survivors are found in the first 72 hours, according to experts. 

With the 72-hour window closing early Thursday morning the likelihood of rescuing survivors falls with every passing hour. 

But that number of people rescued can vary significantly depending on the weather, aftershocks and how quickly rescue teams and equipment can arrive at the scene.

The scale of the disaster and the current weather conditions are currently going against efforts in Turkey and Syria.

The most important thing for the emergency services it to try and get medical attention to as many people under collapsed buildings before they succumb to hyperthermia, their bodies fail or they bleed out.