Organism during thermal climatic changes will undergo certain reversible changes termed as thermal acclimatization which does not interfere with nor affects the genetic mechanisms of the organism but influences the biological and physiological functions to maintain constant homeostasis within the system
Thermal acclimatization prone the organisms to extreme heat conditions so that they can adjust to survive.
The thermal acclimatization change may be acute that lasts for a few minutes to hours and will be reversed or chronic, both acute and chronic changes may influence the cardiac function along with the biochemical and physiological pathways of the organism
Some organisms predict and anticipate climate change and adapt to the thermal acclimatization process gradually
The organism to survive and perform in the varying climatic conditions will undergo certain biochemical changes:
In cold conditions, the fluidity of the organism’s cell membranes will increase. While in extremely warm or thermal temperatures the fluidity of the cell membrane decreases along with an increase in membrane protein synthesis.
Besides membrane proteins organisms also synthesis heat shock proteins that will maintain cellular function in heat stress conditions caused by the temperature change.
Organisms that are constantly acclimatized to high or low temperatures contain heat shock proteins readily available.
In addition to biochemical changes. physiological changes are also exhibited by Organisms for survival in novel environments. Example: Birds often increase their organ size to increase their metabolism during climate change
Physiological Changes in Humans
The two types of heat that are encountered by the human system is humid heat and dry heat. Exposure to both environmental conditions is dangerous for the homeostatic system. Negative homeostatic feedback is exhibited by the body to normal conditions.
During Humid heat conditions the environmental air maintains an increased amount of water vapor and a warm temperature. The increase in water vapor content decreases or prevents evaporation of sweat through which the body’s cooldown mechanism is prevented
In dry heat, the environment consists of less or no water vapor with a warm temperature. Mostly desert maintains dry heat. In this climate evaporation of sweat is faster which results in dehydration due to no content of water vapor
Thermal acclimatization changes produced by humans mostly depends upon the intensity, duration, frequency, and type of heat(humid heat or passive or exercise-induced heat).
The most important thermal acclimatization process through which the human body cools is sweat evaporation
The body signals the hypothalamus when the body reaches a temperature above 35 Â°C (95 Â°F). which leads to skeletal muscle shivering or a rise in body temperature through which vasoconstriction and sweating take place. Further sweat evaporation cools the blood beneath the skin. However, in some cases, dehydration may occur due to low water availability in the body.
The second important physiological thermal acclimatization is to reduce the rate of metabolism, which also helps the body to maintain a stable temperature.
Thermal acclimation further increases the fluid balance, through which the cardiovascular stability of the system is maintained during climate change.