Running down the street and your heart races? Quickly responding to 'this condition' can prevent death

High proportion of deaths due to heatwaves among those aged 65 and older
It can develop into other illnesses beyond heat-related illnesses.

Since last week, the first heatwave advisories have been issued across various parts of the country. This is a week earlier than last year. A heatwave is defined as days when the maximum temperature exceeds 33°C, and if such weather persists for two or more days, a heatwave advisory is issued. If days with a maximum temperature of 35°C or higher are expected to continue for two or more days, a heatwave warning is issued.

Prolonged exposure to heatwaves often causes mild symptoms such as discomfort, fatigue, and decreased concentration. The problem arises when symptoms become severe, leading to heat exhaustion or heatstroke, which can include dizziness, nausea, muscle cramps, and changes in consciousness.

In the event of such an emergency, you should first move to a shaded area with good ventilation or an air-conditioned safe indoor space. If the person is conscious and able to respond well, it is important to have them drink cold water, remove their clothing, and cool their body by spraying water on the skin while using a fan or a hand-held fan. However, if symptoms do not improve after resting, they must visit a medical facility. In cases of seizures, fainting, or decreased consciousness, immediately call 119 to get medical assistance.

Since the majority of deaths due to heatwaves are among the elderly, extra caution is necessary for older adults. Professor Kim Deok-ho of the Emergency Medicine Department at Nowon Eulji Medical Center stated, "Younger people are more prone to less life-threatening conditions such as heat cramps, heat syncope, and heat exhaustion, but in the elderly, there is a higher incidence of heatstroke accompanied by body temperatures over 40°C and neurological symptoms." He added, "In fact, analysis of heat-related illnesses caused by heatwaves shows a higher proportion of deaths among those aged 65 and older, most of which occur outdoors, often while working in fields or on farms." Therefore, it is important to stop activities during the sun's peak hours (11 a.m. to 5 p.m.) and rest in cool places.

The main heat-related illnesses caused by heat are heat exhaustion and heat stroke. The two terms are often confused, but heat exhaustion refers to a condition where the body temperature rises to between 37 and 40 degrees Celsius due to exposure to high temperatures, resulting in dehydration. The phrase "heat stroke" is commonly used, but in the international disease classification code published by the WHO, it is referred to as heat exhaustion. If symptoms such as rapid heartbeat, dizziness, headache, or nausea occur, it is essential to rest in a shaded area.

Heatstroke is more dangerous and has more severe symptoms than heat exhaustion. It is a condition caused by the inability to properly dissipate heat in work or exercise environments where exposure to excessively high temperatures occurs, leading to a sustained hyperthermic state. Symptoms include a body temperature above 40°C, consciousness disturbances, central nervous system abnormalities, and seizures. Additionally, there are other conditions such as ▲heat rash caused by inflammation of sweat glands (prickly heat), ▲heat edema characterized by swelling of the feet and ankles that does not require special treatment, ▲heat syncope resulting from orthostatic hypotension due to peripheral vasodilation and decreased vascular tone, ▲heat cramps caused by excessive loss of salt through sweat leading to muscle spasms, and various symptoms such as headaches caused by insufficient fluid intake and salt loss.

The reason why the elderly are particularly vulnerable to heatwaves is because aging leads to the development of comorbidities and the presence of multiple chronic diseases. These comorbidities interfere with the body's ability to adapt to heatwaves. Aging also causes significant changes in body composition, most notably in total body water. In simple terms, elderly individuals have a reduced total body water volume compared to young adults, making them more susceptible to dehydration and electrolyte imbalances when exposed to high temperatures.

Furthermore, the function of the heart declines, making blood circulation less efficient and making it difficult to easily dissipate heat. The skin and mucous membranes experience reduced subcutaneous blood flow and decreased elasticity, making it difficult for elderly individuals with diabetes or peripheral vascular diseases to dissipate internal heat. As a result, the elderly are more prone to heat exhaustion and heat stroke, and become vulnerable to heatwaves. Their mental cognitive abilities also decline, leading to delayed recognition that they should change into lighter or more heat-dissipating clothing when exposed to heat. This delay in action makes it harder to respond promptly, and they may not realize the need to cool down in a cool place until later.

It is known that the elderly have difficulty sensing thirst even when they are thirsty. This is because the function of the nervous system that transmits signals to the brain and the production of appropriate hormones decline. When our body becomes dehydrated, it reduces water excretion through the kidneys by secreting antidiuretic hormone. An electrolyte imbalance caused by dehydration triggers the secretion of aldosterone hormone to conserve water and salt in the body. Through this process, increased levels of antidiuretic hormone and aldosterone signal the brain to feel thirst. However, comorbid conditions such as diabetes, heart disease, and kidney disease can interfere with this mechanism, and the use of multiple medications can also diminish the sensation of thirst.

Professor Kim Deok-ho stated, "Heatwaves can lead to decreased outdoor activity in the elderly, resulting in muscle loss and mobility impairments, or cause decreased appetite leading to reduced intake, electrolyte imbalances, and nutritional deficiencies." He added, "There are cases where elderly individuals cannot take their usual medications, leading to an acute exacerbation of chronic conditions requiring emergency care." He further emphasized, "It is important to recognize that secondary effects, such as the acute progression of dementia, are characteristic of the elderly, and both the individuals and their caregivers need to respond appropriately to heatwaves."