Death in the Clouds: The Problem with Everest's 200+ Bodies (BBC)
"No one knows exactly how many bodies remain on Mount Everest today, but there are certainly more than 200. Climbers and Sherpas lie tucked into crevasses, buried under avalanche snow and exposed on catchment basin slopes - their limbs sun-bleached and distorted. Most are concealed from view, but some are familiar fixtures on the route to Everest's summit."
Oxygen at High Altitudes (NCBI)
"The areas with the highest mountains are also the areas with the poorest facilities, especially for medical care. Trekkers must therefore understand the effects of altitude on their bodies (hypoxia, cold, and dehydration), the processes of acclimatisation, and prophylaxis against and treatment of altitude illness."
Why Do You Feel So Awful at High Altitudes? (Science Line)
"Your chest heaves, lungs burning, but you can't catch your breath. Your head pounds, vision blurring, but you feel like you'll faint any second. You're definitely fit enough to climb a flight of stairs without trouble - is this some sort of nightmare? Possibly, but if you're up in the mountains, you're more likely experiencing altitude sickness."