Solar fridges could play a vital role in helping aid workers get life-saving vaccines to people in remote parts of developing countries, researchers say.

Engineers have developed a prototype that could keep vaccines at the right temperature until needed.

It is feared thousands of children in Third World countries die from diseases preventable by vaccination.

Tests show the system, designed at Edinburgh University, can produce up to 5kg of ice each day.

The fridge can store vaccines at between two and eight Celsius for as long as three days, the target set by the World Health Organisation.

The team at Edinburgh hope a new, more compact and market-attractive prototype can be developed as a result of their research.