When a sufferer's red blood cells are exposed to low-oxygen conditions, the cells lose their healthy round shape and become sickle-shaped.

The idea was simple enough, a controlled burn under low-oxygen conditions.

In low-oxygen conditions, that could be deadly.

HIF-1 has been shown to be vital to chondrocyte survival, allowing the cells to adapt to low-oxygen conditions within the growth plates of bones.

Red blood cells, for instance, release S-nitrosothiols into the bloodstream under low-oxygen conditions, causing the blood vessels to dilate.

The extinction can be explained by ocean stratification causing low-oxygen conditions in the benthic zone.

The response of naked carp to cold and low-oxygen conditions seem to be at least partly mediated by hypoxia-inducible factor 1 (HIF-1).

These mutated cells, in low-oxygen conditions, have an enormous competitive advantage and soon dominate in the central regions of solid tumors.

Some of these apparently enable it to be very robust, withstanding high salt concentrations or low-oxygen conditions.

They sleep in altitude tents or altitude rooms that simulate the low-oxygen conditions of high altitude.