Things Are Getting Hotter In Here
Extreme heat, its impacts on humans, and why are they becoming more frequent.
It’s June, which can only mean one thing: It’s summertime! However, as much as the month kicks off a well-deserved months-long holiday for many students, June is also the harbinger of the notoriously unbearable summer heat.
However, you might have noticed the summer heat reserved for June to August has become more frequent throughout the year, and your subconsciousness is already rushing to press the air-conditioning button as early as March or April. Welcome to an era of extreme heat, and unlike other natural disasters like typhoons or floods, this weather phenomenon is silent and deadly.
What is extreme heat?
Hotter temperatures are common in places like Hong Kong during the summer since the city is positioned in the Northern Hemisphere, which is tilted towards the sun thanks to the Earth’s axis. Due to the tilt’s direction, the Northern Hemisphere is more exposed to solar radiation and sunlight, which warms up the hemisphere cumulatively.
The characteristics of extreme heat, more commonly described as “heatwaves,” differ from place to place due to the location’s climate conditions. Even though meteorologists don’t have a universal definition for what is defined as a heatwave, experts clarify heatwaves are the effects of persistent and abnormally hot weather, not the cause that leads to hot weather.
Due to Hong Kong’s highly dense urban environment, the city suffers from what scientists call the urban heat island (UHI) effect. Some city areas can feel stifling compared to the countryside due to a high building density and poor airflow, adding to the city’s natural climate patterns of heat and humidity during the summer.
The Hong Kong Observatory is on full alert whenever the weather gets hot. Suppose the temperature and humidity grow high and the winds are weak. In that case, the Observatory will issue the “Hot Weather Special Advisory '' designed to alert the general public on taking appropriate precautions to prepare for hot weather. Whenever Hong Kong is expected to experience temperatures reaching 33 degrees Celsius, a “Very Hot Weather Warning” is initiated. A “Prolonged Heat'' special alert can be issued if hot weather lasts several days and nights, while an “Extremely Hot” special alert would be issued in the case temperatures have reached 35 degrees or above.
How can extreme heat affect the human body?
Anyone in Hong Kong can tell you how uncomfortable it is heading outside in the hot and humid city weather, but it can also lead to health problems if left unattended. Extra heat energy from the environment makes perspiration more difficult as your body tries to cool down, and undissipated heat can lead to a rise in body temperature and cause heat stress.
Heat stress can cause numerous problems to the human body. Heat cramps can occur as a loss of water and salt in the human body causes muscle spasms. Heat exhaustion is similarly experienced due to dehydration, with symptoms including having headaches, feeling nauseous and dizzy, thirsty, irritated, and having a decreased urine output. But the most extreme reaction the body can have when experiencing extreme heat is heat stroke. Hong Kong’s Centre for Health Protection notes sufferers will have convulsions or become unconscious if the symptoms of heat exhaustion are ignored, and the patient will be in great danger if first aid is not administered.
Why are there more hot days, and why is my air conditioning making things worse?
Whenever you are indoors on a hot day, you feel instant relief as the cool breeze of air-con flows through your body. If you are in a room where the air conditioning isn’t on, you would rush to grab the remote and turn the machine on. Although using air-con provides temporary relief from the hot and humid weather, the use of such appliances is making heatwaves worse.
Much of the existing cooling equipment like air conditioners use hydrofluorocarbon refrigerants, potent greenhouse gases that trap heat in the atmosphere and exacerbate the effects of the greenhouse effect. Using coolants also uses a lot of energy, creating a double burden for climate change.
One of the effects of climate change is inevitably extreme heat, especially since the extra heat is conserved within the Earth’s atmosphere due to greenhouse gases, and not enough energy can be dissipated into outer space. 2023 is the warmest year on record, with heat records shattering records by the month. Hong Kong recorded its hottest April in at least 140 years, just the latest high-temperature record broken over the past few months. Around the world, India and neighboring countries have faced their longest heatwave that has caused multiple deaths, millions faced record-high temperatures as a heat dome affected most of the United States, and Mexico’s heatwave plunged multiple cities into rolling blackouts due to strains in the national power grid.
Using cooling equipment like air conditioning forms a vicious cycle: Extreme heat leads to people using air-con to cool themselves down, but in the meantime the energy and greenhouse gases generated by such appliances are emitted to the atmosphere and traps heat, making the weather hotter, and causing people to use more air conditioning!
How to stay safe?
Children, pregnant women, infants, obese people, people with chronic diseases like cardiovascular problems, and the elderly are the most vulnerable to heat stroke. Experts advise the public to take appropriate precautions like bringing and drinking plenty of water to prevent dehydration, or avoiding rigorous and prolonged activities such as hiking and trekking, as some of the basic measures to keep the body cool. When you are safe from heat-related risks, check in with your friends and family with a text or phone call to see if they are okay, especially if they are most vulnerable to heat strokes.
If you are conscious about the environment, you can try using a fan instead of air conditioning if the heat is tolerable. Fans generate much less energy than air-con and do not produce greenhouse gases that exacerbate climate change, not to mention how much it can save your energy bill.