Acclimatization is a process of physiological responses your body makes to a change in environmental conditions. Extreme heat and altitude changes are two environmental conditions for which your body will likely need time to acclimatize for health maintenance. And when proper time isn’t given for acclimatizing changes, then hyperthermia or altitude sickness could be your life threatening consequence.
Heat imposes a physical stress on your body and the primary need for change is to improve its ability to dissipate heat. To improve your body’s tolerance to heat, one acclimatizing change is to better distribute blood to move heat from your core to skin. Therefore, circulation is one acclimatizing change for homeostasis.
One key way to improve circulation is to increase the plasma volume in your blood. Plasma is the liquid your blood cells are suspended in and it is mostly composed of water, so acclimatization thins the blood.
Another circulatory response to heat is vasodilation. Opening your peripheral veins to receive more core warmed blood allows for skin surface blood cooling via the assistance of sweat.
Sweating is another mechanism that undergoes change. For this form of heat acclimatization your sweat will:
- start sooner
- be more diluted
- contain less salt
- double in amount
- be broadly distributed
Generally, time to acclimatize to heat is 10-14 days. And ”heat intolerance” is the inability to develop normal acclimatizing changes even with sufficient time to acclimatize in the heat.
Acclimatization to altitude is the changes required because of the decrease in oxygen concentration. And altitude sickness results if you go too high too fast without appropriating time to acclimatize.
Acclimatizing changes that take place in your body for healthy function while in a depleted oxygen environment include:
- hyperventilation in response to hypoxia
- increase number of red blood cells to transport oxygen
- increase breathing depth to allow for the intake of more oxygen
- increase of 2,4-DPG, a substance that facilitates release of oxygen from hemoglobin
- increase pulmonary artery pressure to force blood into normally unused sections of your lungs
Many experience a mild case of acute mountain sickness during acclimatization. Symptoms that typically occur within a day of your arrival at altitude are:
Although some acclimatize more efficiently to altitude and won’t even notice these symptoms.
Acclimatizing time for altitude is about 3-5 days. If your discomfort during the time required to acclimatize is too severe, then descend and allow for acclimatization at a lower level.