ACCLIMATISATION

The physiological adjustment of living organisms, especially animals and including humans, to changes in their contemporary environment. Rapid movement of humans to high altitudes can result in acute mountain sickness, accompanied by headaches, sickness and lethargy, as a result of lower oxygen concentrations at high altitudes. Drinking plenty of liquid and resting allow acclimatisation to occur over a period of days. Peoples living at high altitudes in the Andes or Himalayas are well acclimatised. A distinction should be made between acclimatisation, acclimation (whereby changes are induced rapidly under artificial, laboratory conditions) and genetic adaptation.

[See alsoevolution]