There’s a reason we send a doctor on every one of our expeditions. Having a medical professional and an expedition first aid kit is hugely important. But while you don’t have to worry about the big things, there are also the tiny bugbears that can throw your day off. Little irritations can become a big nuisance on a multi-day trek. Blistered feet, altitude headaches, or a dodgy tummy can all build up and really hinder the enjoyment of an expedition.