Survival skills
A human being can survive an average of three to five days without the intake of water. The issues presented by the need for water dictate that unnecessary water loss by perspiration be avoided in survival situations. The need for water increases with exercise.
Halicephalobus mephisto
"Halicephalobus mephisto" is resistant to high temperatures, it reproduces asexually, and feeds on subterranean bacteria. According to radiocarbon dating, these worms live in groundwater that is 3,000–12,000 years old. The worms are also able to survive in waters with extremely low levels of oxygen, lower than one percent of the level of most oceans. It is named after Mephistopheles, which means "he who loves not the light" and alludes to the fact it is found so deep under the Earth's surface.