Samuel Peter clambers onto the roof of a rundown building in the town of Akobo in South Sudan.

From his vantage point, the UNICEF electrical engineer can see across the Pibor River and beyond to Ethiopia.

He treads carefully on the rusting metal sheets, not only to stop himself from falling, but because what he is doing is so important: installing solar panels that will power two special refrigerators and help save tens of thousands of lives.

For four years, conflict has gripped South Sudan, the world’s youngest country, displacing nearly four million people. More than half the children have been affected and the health and well-being indicators for mothers and children are among the worst in the world. One in 17 children died before their first birthday in 2016, many from preventable causes.

The refrigerators Peter is installing will become a crucial link in what is known in logistical terms as a “cold chain” – a temperature-controlled supply line that, in this case, safeguards vaccines.

Vaccines must be kept at near-freezing temperatures as they are transported thousands of kilometres from countries where they are produced, like India, to some of the remotest places in the world that UNICEF operates.

UNICEF health workers will use the refrigerators in South Sudan to store thousands of tiny vaccine bottles, which will then be used to immunize mothers and children against diseases such as measles, polio and tetanus.

Read the full article about the solar-powered fridges saving lives in South Sudan by Simon Crittle at UNICEF.