Hiking equipment
According to Tom Brown, the basic plan for survival is in the order of shelter (including clothing), water, fire, and food. Cody Lundin writes about the "Rule of 3s"; this relates to human survival without basics: three minutes without air, three hours without shelter, three days without water, or three weeks without food.
Cryptobiosis
Anhydrobiosis is the most studied form of cryptobiosis and occurs in situations of extreme desiccation. The term "anhydrobiosis" derives from the Greek for "life without water" and is most commonly used for the desiccation tolerance observed in certain invertebrate animals such as bdelloid rotifers, tardigrades, brine shrimp, nematodes, and at least one insect, a species of chironomid ("Polypedilum vanderplanki"). However, other life forms, including the resurrection plant "Craterostigma plantagineum", the majority of plant seeds, and many microorganisms such as bakers' yeast, also exhibit desiccation tolerance. Studies have shown that some anhydrobiotic organisms can survive for decades, even centuries, in the dry state.