On a hot summer’s day, one tends to drink cold drinks and eat cold foods to try cool their body down. But an old Korean proverb states that one should control fire with fire (yiyul-chiyul, 이열치열, 以熱治熱). In other words, instead of drinking cold drinks, it is better for your health if you eat hot soup to combat the heat. When the temperature becomes hot, the body redirects blood flow to the skin to cool itself, meaning there is less blood flow to the organs and causing the internal temperature to drop. Although cooling yourself is good, having a cold drink rapidly on a hot day can suddenly cause a large temperature difference between the surface and the organs, leading to digestive problems. In severe cases, it can cause abdominal pain and diarrhoea, with a vicious cycle where the heat is trapped on the surface and you feel even hotter. Ergo, having a hot food like samgyetang (a Korean chicken soup with many nutritious foods to revitalise your health in the summer) warms the organs and allows for better communication between the organs and the skin to effectively overcome the heat.
The philosophy of yiyul-chiyul can be extended beyond the scopes of medicine. Just as the proverb defeat savages with savages (yiyi-jeyi, 이이제이, 以夷制夷) says, one can control a certain force by using the same force on it. A great example is backfires. A forest fire tends to be too large in area to be extinguished with water. But if you deliberately start a fire just beyond its trajectory, it will burn everything as it moves towards the forest fire. Eventually the two fires will meet and without any fuel to consume, both will be extinguished.
A person’s body temperature is always maintained between 36.5~37.5°C. This is because enzymes, which are crucial in all physiological reactions in the body, work most efficiently at this temperature. As physiology is essentially a series of chemical reactions, it is heavily dependent on temperature. If the temperature falls, chemical reactions occur slower and vice versa. When body temperature falls below 35°C, metabolism becomes too slow and it poses a risk to the person’s health. This is known as hypothermia.
How does hypothermia affect the body? Hypothermia is categorised into three classes depending on the severity.
- Mild hypothermia (32~35°C) leads to the slowing of bodily functions, tremors and difficulty in walking. The patient’s speech is impeded and other neurological symptoms such as decreased judgement skills and confusion start to appear. Also, blood pressure, pulse and breathing rate rise.
- Moderate hypothermia (28~32°C) causes paralysis of muscles and extreme fatigue (they may complain of being sleepy). As blood (carrying heat) is rerouted to major organs, the skin (especially lips and extremities) become white or purple and very cold. Neurological symptoms worsen with amnesia, memory loss, severe confusion and delusion beginning to show. As sustained hypothermia leads to the tremors stopping, one should not take the lack of tremors as a good sign. Heart rate becomes irregular and arrhythmia may occur.
- Severe hypothermia (20~28°C) leads to chemical reactions becoming so slowed that physiological functions that support life decline dramatically. Heart rate, blood pressure and breathing all lower to dangerous levels and the heart and lungs may stop functioning. As the patient’s major organs begin to shut down, they enter a state of unconsciousness and eventually, clinical death.
As you can see, hypothermia is a highly dangerous situation that can kill. There are some other fascinating facts about hypothermia.
20~50% of hypothermia death cases are associated with paradoxical undressing. This is a strange phenomenon where the person begins to take off their clothes due to confusion and a lack of judgement from the hypothermia. One theory suggests it is related to the cold damaging the hypothalamus (which controls body temperature), causing the brain to think that the body temperature is rising. Whatever the reason, it is extremely dangerous as it worsens the hypothermia.
As explained above, severe hypothermia leads to death. But interestingly, hypothermia also protects organs. This is why organs for transplanting are transported in ice. Similarly, there are examples of people who “died” from hypothermia recovering with no brain damage. Because of this, medical professionals traditionally say: “they’re not dead until they’re warm and dead”. In fact, if there is something wrong with the patient’s circulation and there is risk of damage to their organs (such as in surgery), sometimes the patient’s body temperature is forced down with ice water injections and cooling blankets, known as protective hypothermia.
Finding a pencil that’s been chewed,
Telling the time, learning to whistle,
Tying your shoe, for the very first time,
Playing the drums, in your own school band.
Two kinds of ice cream, pizza with sausage,
A warm blanket, a warm puppy,
Knowing a secret,
Walking hand in hand.
Climbing a tree, five different crayons,
Catching a firefly, and setting him free,
Being alone every now and then,
Coming home again.
Having a sister,
Sharing a sandwich, getting along,
Singing together when day is through,
Those who sing with you.
Morning and Evening,
Daytime and nighttime,
Anyone, and anything at all,
That is loved by you.
~ Paraphrased from Peanuts by Charles M. Schulz