Hudson Reynolds had a summer adventure that few can Johnathan Walkercompete with. 

The 16-year-old climbed Mount Kilimanjaro, the highest mountain in Africa. It took six days to reach the summit. At some times, Reynolds was climbing in near-freezing temperatures. 

It was all for a good cause, though: Reynolds was climbing to raise awareness and research money for PKU, a rare disease that affects just 16,000 Americans. One of those affected people is Reynolds' older sister Tia. 

"What (Tia has had) to go through her whole life just doesn't compare to climbing Kilimanjaro, no matter how hard it was," Reynolds said. 

Reynolds' climb raised $200,000 dollars to battle PKU, which makes food protein toxic to the brain. Tia Reynolds told CBS News that she was "inspired" watching her brother climb the mountain in her name. 

Battling the disease is a family affair. The children's mother skied across Norway to raise money. Their grandfather biked across America, and their grandmother skied the North and South Poles. These efforts have raised millions which led to a medical breakthrough: A daily shot that can manage PKU. However, it's an expensive medication that isn't always covered by insurance. 

The family is still working to do more to treat PKU. The next mountain Reynolds hopes they climb is the one that leads to a cure.

"I love that we are working on this together," Tia Reynolds said. 

Kris Van Cleave

Kris Van Cleave is CBS News' senior transportation and national correspondent based in Phoenix.

Twitter