How earthquake rescues work

Rescuers work in Pescara del Tronto, central Italy (Reuters)
Rescuers work in Pescara del Tronto, central Italy (Reuters)

The 6.2-magnitude earthquake which hit central Italy on Wednesday sparked a massive rescue and recovery operation.

It's a race against time to get to the survivors - what's involved in such a large-scale search and rescue operation?

Firstly, rescue workers assess where they're most likely to find survivors, which can often be in the voids created where large concrete beams fall.

Video cameras with thermal imaging are mounted on flexible poles that can squeeze through small gaps and detect people's body heat.

The use of rescue dogs is vital because their acute sense of smell can detect signs of life which humans can't.

High tech robots with ultrasonic sensors and infrared cameras are also used for this reason.

Special carbon dioxide detectors can identify the breath of an unconscious person who may be trapped, and then they're loaded onto a cart with an on-board oxygen canister and taken to safety.