Also in July, the first major heat wave of the summer hit Spain, affecting 14 communities that remained on alert due to high temperatures, above 40ºC in different provinces.
These extreme temperatures are extremely harmful to health, but how does the human body react to an increase in temperature?
The normal temperature of a human being ranges between 35° and 37°C and is usually constant. If the temperature rises above 37°C we speak of fever, while if it falls below 35°C, we speak of hypothermia.
How does the human body regulate temperature?
The body temperature regulator is the hypothalamus , which is a small region located at the base of our brain, near the pituitary gland. Although it is small, it is very important and plays a crucial role in:
The regulation of body temperature.
Regulation of heart rate.
Regulation of thirst.
The regulation of hunger.
The regulation of sleep cycles.
Regulation of blood pressure (homeostasis).
The release of certain hormones that trigger the production of other hormones by different glands in different parts of the body.
The hypothalamus is very sensitive to changes in temperature in our body. In fact, if temperatures exceed 40°C, our hypothalamus stops working properly, which can even cause death from heat stroke.
location of the hypothalamus in our brain
What mechanisms does the hypothalamus put in place to cool us down?
The hypothalamus uses thermoreceptors to obtain information about our body temperature. When it detects an increase in temperature, it triggers a series of mechanisms to keep our body at an optimal temperature (37ºC). kuwait whatsapp number list The temperature at which the blood reaches the hypothalamus will be the main determinant of the body's response to thermal changes.
The anterior portion, composed of parasympathetic centers, is responsible for dissipating heat. It is the region involved in lowering temperature.
The posterior portion, with sympathetic centers, preserves and maintains body temperature. It is the region involved in increasing temperature.
As the temperature increases, the anterior portion is activated and the posterior portion is inhibited.
Inhibition of this posterior portion produces: Decreased metabolism and decreased muscle tone .
Activation of the anterior portion of the hypothalamus triggers two mechanisms to decrease body temperature :
Perspiration : This is the most important cooling system available to our body. When it detects an increase in temperature, the hypothalamus triggers the production of sweat . This is produced by the sweat glands in the skin. Sweat, which is made up of water, mineral salts and toxins, is expelled through the pores of our skin. When sweat evaporates from the surface of our skin, it releases excess heat and keeps our temperature constant. We evaporate between one and two litres of sweat every day, and this can reach up to 6 litres per day. In order to evaporate through sweating, the body needs to have water available (so we must be well hydrated) and a good functioning of the heart and cardiovascular system, to bring a large amount of blood to the skin and for the blood to provide the necessary water to the sweat glands.
Vasodilation : Capillaries are the blood vessels with the smallest diameter and are closest to the surface of the skin. The blood that circulates through them is therefore closer to the outside air than the blood in the rest of our blood vessels. When the capillary dilates, a greater quantity of blood is exposed to the air, which allows it to cool and our body temperature to be maintained.
Therefore, perspiration and vasodilation are the fundamental mechanisms that our body uses to maintain a constant temperature.
Effects of heat stroke
If we reach the point where our body is exposed to extreme heat, reaching an internal temperature of around 40 degrees, we can suffer heat stroke . This is characterized by two main phenomena: an increase in body temperature (hyperthermia) and effects on the nervous system . Hence, the first signs that our body collapses in the face of heat are a sensation of extreme heat combined with a general feeling of malaise.
Some of the characteristic symptoms of heat stroke are fatigue , weakness , confusion , headaches , nausea , vomiting , anxiety , dizziness , tachycardia and drowsiness . In some cases, although less frequent, jaundice (yellowish skin), muscle tenderness, hypotension, gastrointestinal bleeding, bruising and bleeding of the skin also occur. In extreme cases, these symptoms can lead to loss of consciousness (fainting), multiple organ failure and death.
Although heat stroke can affect anyone, those most susceptible are:
Sedentary, elderly or weak people exposed to extreme heat conditions for days.
Physically active people occasionally exposed to extreme heat situations due to excessive physical effort or activity.
prevent the body's reaction to high temperatures
Heat-related disorders
Dehydration exhaustion . This is a systemic reaction secondary to prolonged exposure to heat with loss of water and salts. Symptoms: intense thirst, headache, dizziness, fatigue, irritability, hypotension, tachycardia and hyperventilation.
Cramps : These are painful spasms of the muscles of the abdomen and extremities due to the loss of salts and electrolytes.
Syncope . This is a symptom indicating that there is an insufficient supply of blood, oxygen or glucose to the brain. Symptoms: a feeling of dizziness, blurred vision and postural wobbling. Fainting usually does not last long and recovery is rapid.
Heat stroke . Heat stroke occurs when the body loses control of body temperature, which rises above 40ºC, causing damage to cellular structures and the thermoregulatory system, with a high risk of mortality. Symptoms: reduction or cessation of sweating (early symptom), headache, dizziness, confusion, tachycardia, hot and dry skin, unconsciousness and convulsions. Complications include adult respiratory distress syndrome (rapid and labored breathing, shortness of breath, low blood pressure and organ failure), kidney failure, liver failure and disseminated intravascular coagulation. The elderly are more susceptible to suffering a heat-related event.