Heat and Heart Diseases

Our body needs a certain temperature in order to survive. For our normal body functions, body temperature must remain constant at 36.6 C. According to the changing temperature of the external environment, some heat regulation mechanisms in our body are activated and prevent the change in body temperature.

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Sweating and the evaporation of sweat result in heat loss from the body. The dilation of blood vessels under the skin increases blood circulation in the skin, helping to reduce body temperature. This condition leads to a drop in blood pressure and an increase in pulse rate. In cold environments, the blood vessels under the skin constrict, reducing heat loss from the body and causing a sensation of coldness in extremities such as hands and feet. To balance body temperature, the heart pumps more blood to the skin’s blood vessels, increasing the workload on the heart and causing it to beat faster. This situation is not favorable for patients with coronary artery disease, as it leads to fatigue in the heart and a decrease in blood flow to the heart muscle, resulting in chest pains. Some pulse-slowing medications used in heart patients may negatively affect the efficient functioning of the body’s cooling system, causing patients to feel the heat more intensely.

External temperature and perceived temperature are different. The perceived temperature is also influenced by external humidity. As humidity increases, the perceived temperature rises. Higher humidity reduces the evaporation of sweat, leading to an increase in the perceived temperature. Therefore, temperature increases are more noticeable near the seaside.

The mildest condition caused by high temperatures is heat exhaustion. It is associated with the loss of water and salt through sweating. Symptoms include weakness, headache, dizziness, and muscle cramps in the arms, legs, and abdomen. It is commonly observed in individuals engaged in heavy work or exercising in high temperatures. In the case of heat exhaustion, the patient should be moved to a cool or shaded place, clothing should be removed, and the person should be rested until the complaints subside. A cold shower can be given, and efforts should be made to ensure adequate fluid intake. Avoiding alcohol, caffeine, and sugary drinks that contribute to fluid loss is recommended. If symptoms persist for more than 1 hour, seeking medical attention is advisable.

Heatstroke is a serious condition where body temperature rises above 39°C. The skin becomes dry, hot, and red. Severe headache occurs. The pulse is rapid, and there may be nausea, dizziness, and altered consciousness. Vomiting and involuntary movements may occur. The patient should be moved to a cool environment, cooling techniques such as applying ice or wet towels should be used, and immediate medical attention is essential.

Who is adversely affected by heat?

Elderly individuals and children under 4 years old, Those with chronic kidney failure, undergoing dialysis, Obese individuals, pregnant women, those who work outdoors (such as agricultural and construction workers), those working in hot and humid places like bakeries and dry cleaners, individuals exercising and playing sports outdoors, Medications that increase sensitivity to heat negatively affect the body’s temperature regulation system and lower the heat tolerance (such as psychiatric medications, tranquilizers, and some medications used in Parkinson’s disease), Inadequate fluid intake, alcohol consumers, Coronary artery disease patients, those with stents or replaced heart valves, those using blood thinners, individuals with heart failure, hypertensive patients, diabetic patients, Restrictions on daily fluid intake for heart failure and some kidney patients may lead to problems in coping with increased loss during excessive heat. Patients with heart failure cannot pump the amount of blood needed to cool the body. Medications used in the treatment of heart failure may have negative effects on mechanisms that adapt to hot weather.

The body’s reaction to high temperatures, including sweating, a decrease in blood pressure, and an increase in pulse rate, can be harmful to heart patients. Excessive fluid loss reduces blood viscosity in coronary heart patients. Excessive fluid loss can trigger a heart attack by causing clot formation on coronary artery narrowings.

*Diuretics promote the excretion of water and salt from the body through the urinary system. If sweating increases water and salt loss through sweating in hot weather, dehydration, a condition of becoming dehydrated, occurs, and the blood becomes thicker. The urea level in the blood rises, affecting the elimination of other drugs taken.

*Beta-blockers slow down heart rate, and heart rate may not increase sufficiently to cool the body in order to counteract heat.

*In the use of antihypertensive drugs, the degree of blood pressure drop due to heat increases, causing complaints such as weakness, easy fatigue, and dizziness upon standing.

General precautions:

Avoid walking, exercising, or engaging in activities during the hottest hours of the day; prefer early morning or late afternoon hours. Avoid staying in a parked car during extremely high temperatures.

Drink plenty of water and avoid alcohol, caffeine, and sugary drinks. Individuals working outdoors should consume at least 2 cups of water per hour. Tea and coffee increase water loss with their diuretic effect. Alcoholic beverages can be consumed in small quantities and in the evening. Eat small amounts of easily digestible food frequently. Reduce the consumption of foods with high protein and fat content.

Stay in air-conditioned cool environments. If there is no air conditioning, wash hands and face frequently or take a shower. Wear light, breathable (cotton), light-colored, loose-fitting clothes, and use a light-colored hat and sunglasses. Apply sunscreen with a high protection factor to areas exposed to the sun.

Patients with heart conditions should be under the control of a doctor in terms of treatment and medication doses, and they should implement necessary changes according to recommendations.

Did you know?

Our body is composed of 75% water. The brain is 85%, blood is 90%, muscles are 75%, kidneys are 82%, and bones are 22% water. Maintaining the balance of water in the body ensures the proper functioning of metabolism and normal blood flow. Daily water consumption should be at least 2 liters.

We sweat a lot in hot weather, but we don’t need to consume a lot of salt. Even in very high temperatures, the loss of salt through sweating is not excessive.

Not only the elderly but individuals of all ages should be mindful of salt consumption. Excessive salt intake can raise blood pressure.

The salty taste of foods may not be perceived, and individuals consuming excessive salt may experience a desensitization of taste buds on