Regarding the change in the body s response to temperature, the human body has a sensory problem

The human body's feeling of temperature mainly depends on the regulation of the human body, the normal body temperature of the human body is 37 degrees, under normal circumstances, the heat is dissipated to ensure the normal body temperature, the range of downward adjustment is larger, about -10 degrees, the temperature is about 23 degrees and feels more comfortable, and then it feels cold. Similarly, high temperatures are not conducive to the dissipation of body heat, so the range of upward adjustment will be small. And, of course, there is the effect of air flow, which accelerates the evaporation of heat.

Under normal circumstances, it refers to the condition that the humidity is suitable (such as 50%) and does not expose to direct sunlight. At around 30 degrees Celsius, the human body feels the best, and even when sleeping, it rarely catches a cold. Above 33 degrees Celsius, the body begins to feel hot, and sweat glands begin to activate and secrete sweat for evaporation and cooling.

No, the body temperature has been around 37 degrees Celsius.

Scientists do not yet have a definitive answer to the phenomenon of constant body temperature, but there is a hypothesis that the brain is best functioning at a constant temperature, so in long-term natural selection, animals with a constant temperature are selected.

Of course, the survival methods chosen by the lower animals with simple brains are different, but they are the most favorable environment for them. For us humans, constant temperature is the best choice.

In fact, keeping the brain at a constant temperature is not the only reason for homeothermic animals to maintain a constant temperature. When the temperature rises, the chemical reaction generally accelerates, so turning the body into a thermostat with a higher temperature can promote the body's activity to some extent.

But there is a limit to this reaction, and when the excess heat cannot be dissipated and the information comes too quickly, the system will collapse. Over the past few million years, humans, as well as other mammals and birds, seem to have discovered that the optimal temperature is around 37.

We found that the perceived temperature is not the same as the actual temperature because they are measured and felt differently.

We must know that the body temperature is the temperature we actually feel, it is what our human body feels, and it is not fixed, and the body temperature is sometimes related to our mood or the amount of clothing. However, the actual temperature and the perceived temperature are completely different.

The actual temperature is measured by the weather station, and the temperature is announced every day, and the actual temperature is the same in each area and does not vary from person to person. It is a more scientific measurement of the standard of comparison. The body temperature is different from person to person, according to our own physique, the amount of clothes, or the mood can slightly determine our body temperature.

Sometimes the difference between the perceived temperature and the actual temperature is quite large, for example, in the summer, the actual temperature may not be particularly high, but in the summer, the temperature we feel, the perceived temperature is very high, which is the difference between the two.

Because the actual temperature does not fully represent our physical temperature, the actual temperature only represents the cold and warm of the air, and there are too many factors affecting the cold and warmth of our human body.

If the relative humidity of the air is higher when the weather is hotter, it will make us feel hotter than the actual temperature, and if the relative humidity is small, we will also feel better, and the wind speed is also very related to it.

Therefore, we must pay attention to our body temperature when we go out, and don't rely on the actual temperature we know to determine how much we are wearing. Because this judgment is one-sided, it may have a little effect on our body.

If you understand the structure and use of thermometers commonly used in the human body, you can understand the reason.

1. The commonly used thermometer uses the principle of thermal expansion and contraction of mercury liquid (mercury). Its accuracy is 2, and there is a very thin and slightly curved thin tube between its glass bubble and the straight tube.

When taking a person's body temperature, it can be taken away from the human body because the mercury contraction will break off from the elbow, and the mercury in the straight tube will not fall into the glass bubble. Therefore, the mercury in the straight tube should be shaken vigorously a few times before use to return to the glass bubble before it can be measured.

3. From the above knowledge, it can be seen that if the mercury is disconnected at the elbow,At room temperature (20), the thermometer commonly used in the human body will not change with the change of external temperature.

No, changes with the outside temperature are called thermometers.

The thermometer will be very thin in one place near the mercury ball below, and when the temperature suddenly cools, the mercury in the very thin place will break. This prevents the upper part of the mercury from flowing back and stays in its original position, preserving the temperature at the right time for the measurement. When it is time to use it again, the thermometer needs to be shaken vigorously to allow the mercury column to flow back.

As we all know, the temperature of the human body is about 37 degrees, and it is often kept within a relatively stable range, too high or too low, will affect the normal operation of human body functions. Since the human body temperature is 37 degrees, why do people feel particularly hot when the ambient temperature exceeds 30 degrees?

The more comfortable temperature perceived by the human body is: summer, 19-24, winter: 17-22.

Human activities need energy, and energy is produced in the form of metabolism, the transformation of energy can not be all converted into mechanical energy, the same is true in the human body, part of the chemical energy of food in the process of transformation is emitted in the form of heat energy, and there will naturally be body temperature. When the excess body temperature is dispersed faster in the process of evaporation, the human body will feel very cool, and if the body temperature is slow to dissipate heat, the heat will gather in the human body, and it will feel very hot. Therefore, the perceived comfort of the human body is related to the speed of heat dissipation (of course, when the ambient temperature is very low, the heat of the human body is dissipated too quickly, and it will feel cold).

When the ambient temperature exceeds 30 degrees, due to the high temperature of the outside world, the heat dissipation of the human body is slower, and the heat accumulated in the human body cannot be discharged in time, which also becomes the cause of the human body feeling hotter.

A large part of the heat of the human body is discharged from the body through the evaporation of the body surface and sweat, so when the outside temperature exceeds 30 degrees, the heat of the human body cannot be well evaporated with the ambient temperature, which affects the heat dissipation efficiency and causes the human body to dissipate heat slowly. It is therefore the reason why people feel hotter; Within the range of comfortable temperature, the heat generated by the human body and the heat dissipation form a balance point, and the human body feels more comfortable; When the ambient temperature is low, the heat dissipation is significantly accelerated, and the heat of the human body can no longer meet the needs of the body's functions, which will lead to the phenomenon of feeling colder. The effect of ambient temperature on the human body is mainly that it determines the efficiency of heat dissipation (of course, it is also related to the speed of air flow).