What harm does high temperature have on the human body?

In many areas, the temperature is very high. If people live in such an environment for a long time, it may not be as simple as heatstroke. Moreover, in modern society, some people work in high-temperature workshops for a long time. As a result, they suffer from some diseases after working for only a few years. Isn't this enough to prove the harm of high temperature to the human body? Then the question is, what are the harms of high temperature to the human body?

Direct Damage

High temperature directly affects the structure of the cytoplasm, causing symptoms to appear in a short period of time and can spread from the heated area to the non-heated area. Possible causes of injury include:

(1) Protein denaturation

High temperature destroys the spatial configuration of proteins and causes them to lose their original biological properties. Protein denaturation is initially reversible, but under continued high temperature, it quickly turns into an irreversible coagulation state.

In general, for plant organs, the less water content in cells, the stronger their heat resistance. Therefore, the drier the seeds are, the stronger their heat resistance is; the more water the seedlings contain, the less heat-resistant they are.

(2) Lipid liquefaction

Biological membranes are mainly composed of proteins and lipids. At high temperatures (about 55°C), the lipids on the membrane can liquefy, and the lipids in the membrane are released to form some liquefied vesicles. The structure of the membrane is destroyed, causing the membrane to lose its semipermeability and active absorption properties. The degree of lipid liquefaction depends on the degree of saturation of fatty acids. The more saturated fatty acids there are, the more difficult it is to liquefy and the stronger its heat resistance. For example, the saturated fatty acid content of heat-resistant algae is significantly higher than that of mesophytic algae.

Indirect damage

Indirect damage refers to the metabolic abnormalities caused by high temperature, which gradually harm the plants. The process is slow. High temperatures often cause excessive transpiration and water loss in plants, which is similar to drought damage. The loss of water in cells causes a series of metabolic disorders, leading to poor growth.

(1) Hunger

Because the optimum temperature for photosynthesis is generally lower than the optimum temperature for respiration, respiration is greater than photosynthesis under high temperatures, that is, consumption is greater than synthesis. If the high temperature lasts too long, the plant will starve or even die.

The temperature at which the respiration rate and photosynthetic rate are equal is called the temperature compensation point. When the temperature is higher than the compensation point, the nutrients stored in the body will be consumed, and the content of starch and protein will be significantly reduced. Starvation may also result from impaired transport or reduced sink capacity.

(2) Toxicity

Under high temperatures, the solubility of oxygen decreases, the aerobic respiration of plants is inhibited, and the anaerobic respiration is enhanced, causing the accumulation of toxic substances such as ethanol and acetaldehyde. Increasing the oxygen partial pressure at high temperatures can significantly reduce heat damage. At the same time, high temperature will inhibit the synthesis of nitrogen-containing compounds, promote protein degradation, and cause excessive accumulation of ammonia in the body, poisoning cells.

(3) Lack of certain metabolites

High temperature inhibits certain biochemical links, causing a lack of active substances such as vitamins and nucleotides necessary for plant growth, leading to poor plant growth or damage.

(4) Decreased protein synthesis

High temperature can induce cells to produce autolytic hydrolases, or lysosomes to rupture and release hydrolases, leading to protein degradation; high temperature can also destroy the coupling of oxidative phosphorylation, resulting in a lack of energy for protein biosynthesis. In addition, the biological activity of ribosomes and nucleic acids decreases under high temperatures, fundamentally reducing the ability to synthesize proteins.