Médecins Sans Frontières (MSF) is working in Doro and Jamam refugee camps in South Sudan. About 80,000 refugees have fled to the camps to escape ongoing violence in Blue Nile state, and MSF -- working against the clock -- is trying to help as many as possible before seasonal rains at the end of the month make the area inaccessible. British doctor Kirrily de Polnay talks about her work in the camps and warns that aid organisations need to urgently accelerate their activities if disaster is to be avoided.