"Heat shock" can also occur in winter, so be careful when taking a bath!

Audit expert: Peng Guoqiu

Deputy Chief Physician, Fourth Medical Center, PLA General Hospital

In the cold winter, taking a hot bath in a warm bathroom is the best choice for people to relax and dispel the cold. But do you know that such a combination of cold and hot can cause "heat shock", which is prone to accidental injuries or even life-threatening! What is heat shock? What should you pay attention to when taking a bath in winter?

01 What is heat shock?

When taking a bath, if the water temperature is too high or the bathroom environment is too hot, the body will sweat too much, the blood vessels will dilate, and the blood pressure will drop, which will cause shock. The main reason is that the temperature change is too drastic.

Some people may not be able to bear the stress of the temperature difference, which may lead to sudden stroke or cardiovascular disease, but in severe cases, it may cause sudden shock.

02 What is shock?

Shock is caused by a sharp drop in effective circulating blood volume and severe lack of blood perfusion to tissues, which leads to functional, metabolic disorders and structural damage to important organs.

In simple terms, if the human body is compared to a city, then the blood vessels are like the water pipes in the city. When certain reasons cause a lack of water in the water circulation system, the city of the human body becomes completely paralyzed, and this is shock.

Common causes of shock include severe blood loss, extensive burns, severe infection, etc. In clinical practice, there is a type of shock caused by increased temperature, such as heat stroke and heat shock.

03 What is the difference between shock and heat stroke?

Although both are caused by heat, the pathogenesis of heat stroke and heat shock is different.

Heatstroke is caused by prolonged exposure to a high temperature and airtight environment, which results in excessive heat in the body, massive sweat loss, and dysfunction of the body's temperature regulation center, leading to high fever, dizziness, headache, confusion, etc. In severe cases, it can lead to multiple organ failure and even death. Heatstroke often occurs in midsummer.

Heat shock is caused by a sudden change in ambient temperature, which leads to large fluctuations in blood pressure and puts a great burden on the body. It may cause serious symptoms such as fainting, arrhythmia, cerebral stroke, myocardial infarction, and even death in severe cases. The incidence of heat shock is very high in winter.

People with vascular-related diseases are more susceptible to heat shock.

Heat shock is mainly caused by drastic fluctuations in blood pressure and rapid contraction and expansion of blood vessels, which lead to adverse consequences. Therefore, most people who are affected have vascular-related diseases, such as arteriosclerosis, diabetes, hypertension, obesity, hyperlipidemia, hyperuricemia, the elderly, and people with bad living habits. Therefore, people with these underlying diseases need to be especially careful!

In addition, although we cannot feel it ourselves, the body is constantly sweating when the water temperature is high. So if we soak for too long, our body will start to become dehydrated and we will feel thirsty. We will also feel tired after soaking for a long time because the increase in temperature will increase our metabolism. Those who take a bath on an empty stomach may even faint due to low blood sugar.

04Is showering safer than taking a bath?

Not necessarily. On the one hand, if you stand under the shower for a long time, the blood will flow to your legs due to gravity, which will reduce the amount of blood returning to the heart, that is, the heart can redistribute less blood to the whole body, so it is easy to faint.

On the other hand, the body can originally excite the sympathetic nerves to compensate for the above process, but for some people, due to individual differences, this mechanism is not activated, and the vagus nerve is activated instead, which plays a completely opposite role to the sympathetic nerves, further reducing the amount of blood returning to the heart. This situation is called vasovagal syncope.

This actually doesn't just happen when you're taking a shower. For example, during military training, you may have experienced fainting while standing at attention. Most of the time, it's due to the two principles mentioned above.

At this time, it is easy for hands, feet and lips to become numb, dizzy, and unstable. Some people will even break out in cold sweats. If this happens, in addition to calling for help as soon as possible, you can immediately lie down and raise your lower limbs to allow blood to flow back to the heart as much as possible.

05Beware of inappropriate times for bathing

On an empty stomach or after a full meal: Bathing at this time will affect digestion and cause insufficient blood supply to the heart and brain. Bathing on an empty stomach can easily cause hypoglycemia.

After drinking: Due to the stimulation of alcohol, taking a bath after drinking will cause blood vessels to dilate rapidly, resulting in low blood pressure, and people will easily become dizzy and unsteady.

After exercise or when you are overly tired: the body is prone to hypoxia and ischemia after being stimulated by hot water, the heart cannot bear it, and accidents may even occur.

If the fever has not subsided or after injecting insulin: taking a bath at this time may cause severe chills, hypoglycemia, dizziness and drastic changes in body temperature.

Safety measures to prevent "heat shock" from bathing

Raise the temperature of your locker room and bathroom before bathing;

When bathing, the water temperature should be controlled below 41 degrees, and it is best not to take more than 10 minutes;

Don’t stand up suddenly from the water after taking a bath;

Do not take a shower immediately after eating, drinking, or taking certain medications;

Inform people around you before taking a bath to prevent accidents.