apex (altitude physiology expeditions) apex (altitude physiology expeditions) apex (altitude physiology expeditions) is a high altitude medical research charity. it is based in edinburgh, scotland, and was founded in 2000. it has conducted six high altitude research expeditions to bolivia and kilimanjaro. previous expeditions have travelled to chacaltaya in bolivia. the next expedition, apex 6, will take place at huayna potosi in bolivia in june 2021. the expedition aims to research the physiology of high altitude pulmonary edema (hape), the effects of high altitude on menstrual bleeding, cognition and sleep. apex administers the hape database, a research registry for individuals who are susceptible to hape or high altitude cerebral edema (hace).