Gregg Mitchley is about to embark on a massive walk from Johannesburg all the way to Durban to raise funds for two young South African children, Jesse and Sadie Krause, who are battling a rare immune condition and currently need specialised treatment overseas.

The condition, called DOCK8 deficiency, leaves their immune systems extremely vulnerable, meaning even a small infection can become life-threatening, and the best treatment available is a specialised bone marrow transplant.

So Gregg has decided to literally put his body on the line and walk hundreds of kilometres to help raise funds and awareness for them.