Acclimatization

Two alpinists

Acclimatization, uh kly muh tuh ZAY shuhn. It is a common misconception that acclimatization and acclimation are synonymous. There is a clear difference to be noted. The word acclimitization is used to describe the process of an organism adjusting to changes in its environment, often involving temperature or climate. Acclimatization usually occurs in a short time, and within one organism's lifetime (compare adaptation). This may be a discrete occurrence or may instead represent part of a periodic cycle, such as a mammal shedding heavy winter fur in favour of a lighter summer coat. Where acclimitization occurs naturally, in the field of physiology acclimation is used to describe the process of an organism being forced to adjust to changes in their environment by artificial means, such as in a laboratory setting (Schmidt-Neilsen 1990).

Plants

Many plants, such as maple trees, irises, and tomatoes, can survive freezing temperatures if the temperature gradually drops lower and lower each night over a period of days or weeks. The same drop might kill them if it occurred suddenly. This process is called hardening and involves several changes, such as a decrease in the water content and an increase in the sugar content of the plant, lowering the freezing point of sap.

Animals

Animals acclimatize in many ways. Sheep grow very thick wool in cold, damp climates. Most human beings become short of breath and tire easily when they move to higher altitudes. After the body adjusts to the new altitude, the symptoms disappear.

Fish are able to adjust only gradually to changes in water temperature and quality. Tropical fish sold at pet stores are often kept in acclimation bags until this process is complete.

Humans

It is important for humans to acclimatize to a new environment before doing strenous activities. When people move from a cool or temperate environment to a hot, dry desert environment or vice versa, they must spend up to seven days acclimatizing to the change in their environment. This lets the body make internal adjustments (see Homeostasis) to compensate for the change in environment conditions. If the acclimatization process is ignored, then the person is at higher risk for heat related injuries (heat stroke, heat cramps, pneumonia). The duration for the acclimatization process can be shortened by pre-emptively spending time in environments much like the new environment you're expecting to be in. Military units will spend time in an environment much like their future theater of operations so that they can hit the ground running.

See also

• altitude sickness

References

• World Book encycopedia 1989

Schmidt-Nielsen, Knut. Animal Physiology: adaptation and environment. 4th Ed. Cambridge ; New York : Cambridge University Press, 1990.