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Heat Wave in the West

Across the globe, we’ve been experiencing more hot days and fewer cold days. Recently, an extreme heat wave affected Western North America such as Northern California, Oregon and Washington in the US and British Columbia in Canada. In Lytton, British Columbia, it reached a record high of 49.6℃ (121.3F). There are numerous wildfire fatalities on the west coast of Canada and the US. This extreme climate change is threatening. It is important to know the causes and consequences behind the horrible toll.

What is a heat wave?

A heat wave is a long period of unusually hot weather that lasts two or more days. To be classified as a heat wave, the temperatures have to be beyond the historical averages of that region. It may also come with a high level of humidity.

How are heat waves formed?

Heat waves are formed when high-pressure air settles high in the air and forces hot air downwards. This creates a bubble or a dome that traps heat near the ground. This dome prevents convection current. It seals the rising air that forms clouds and rain, which both can help cool the air down.

Image is courtesy of directenergy.

Climate Change and heat wave

We are all familiar with climate change which is caused by the accumulation of greenhouse gases in the atmosphere. This increases the frequency and intensity of extremely hot weather. Climate change may also cause changes in wind, humidity and heat circulation patterns which ultimately contribute to extreme weather events. Heat waves are a common indicator of global warming and climate change. From the following graphs, it is shown that the frequency has increased from two heat waves per year to six. Here are more articles about temperature rise and the environment.

Image is courtesy of epa.gov


Health impact

The recent record-breaking heat wave in the Pacific Northwest results in up to 800 sudden deaths in a single week in British Columbia. Many of the deaths are caused by hyperthermia which is a group of conditions characterized by unusual high body temperatures.

  • Dehydration is one of the common illnesses. Sweating is the body’s natural cooling defence. The more you sweat, the more water your body loses. Eventually, dehydration can even affect people’s cognitive ability, preventing the brain from sending signals to the rest of the body.

  • Heat exhaustion can be identified with symptoms like extreme fatigue, nausea, fast and shallow breathing, dizziness, etc. If left untreated, it may lead to heatstroke.

  • Heatstroke is another common yet fatal condition. Normally, the human body can cool down through sweating. When the air is too hot and humid, sweat cannot evaporate quickly enough and results in the loss of ability to control body temperature. When the body’s sweating and cool mechanism fails, it leads to a rapid rise in temperature. The body gets so hot that it starts to denature the proteins which may result in organ failure.

  • Extreme heat is also associated with mental health such as irritability, depression and an increase in suicide rate. People with schizophrenia or other mental illness may change mood disorders because of the changes in temperature.

  • Heat waves also exacerbate the air quality. Since the air is stiff, it traps emitted pollutants and results in poorer air quality and higher ozone levels. This may aggravate the vulnerable population who have existing cardiovascular and respiratory diseases.


Extreme heat can lead to other natural disasters like wildfires and droughts. Plants are just as susceptible to high temperatures as humans. Heat waves lead to water shortage which increases heat stress for plants. The hot and dry condition favours the start of forest fires, just like the recent event in British Columbia. More than 100 wildfires took place across the province. In Lytton, residents have to evacuate due to the wildfire. Heat waves result in the loss of forests and vegetation. It also dries up aquatic ecosystems and accelerates glacier melt. For example, the 2003 European heat wave resulted in 10% loss in glacier mass in Europe. Over time, the grave repercussions of heat waves continue to aggravate the environment and pose negative ecological impacts.

Homeless and Low-income people

People who are homeless are at extreme risk of having heat-related diseases due to the limited air conditioning. Living in a cramped environment with extreme heat conditions, other problems may arise such as insomnia, food spoilage, alcohol or drug abuse, etc. They will also be in misery as more burden is added to their life. Ultimately, they may resort to alcohol or drugs to escape from the distress.


This may not be as significant as you think but heat waves pose an impact on the economic sector. In the agricultural sector, due to the extreme weather and droughts, farmers experience falling harvests and livestock. Scorching temperatures and declining rainfall impact grassland production for animals. Moreover, some animals may experience physical and mental impact as well which result in a reduction in milk production. Smaller productions and higher demand will result in higher prices for consumers as well. The construction sector is also affected severely. Globally, 2% of the total working hours is estimated to be lost either because it is too hot to work or the lost productivity. As for the household. The increased use of energy for cooling may result in a tremendous increase in an economic cost to residents, businesses and governments. Air-conditioning is viewed as a basic necessity, not just for comfort, it’s crucial for survival especially for medical care.

Safety Precautions

Since heat waves are not something that can be avoided easily, learning how to stay safe is necessary. Here are some tips recommended by American Red Cross.

Check heatwave alerts from the government

The National Weather Service has different types of warnings. An excessive heat outlook is usually issued when there is a potential extreme hot weather in the next 3-7 days. A heat watch is issued when there is a higher possibility of an excessive heat event in the next 24-72 hours. Heat waves warning or advisory are issued within 12 hours of the dangerous event. Make sure to look out for notifications from the government or local weather forecasters.

Stay hydrated

Drinking water is one of the essential things you can do to prevent hyperthermia. Avoid sugary, caffeinated and alcoholic drinks as these potentially cause dehydration. Have regular meals, snacks or sports drinks with adequate water intake to replenish electrolytes lost from sweating. Remember to bring a water bottle around you all the time.

Keep your home cool

If you do not have air-conditioning at home, find a place where you can stay cool. Contact nearby neighbours or friends who have air conditioning. Check whether shopping malls, cafes or public libraries are open. Also, find out if your community opens public cooling centres for extreme heat conditions. During the heat wave, wear appropriate clothing such as lightweight, light-coloured and loose-fitting clothing. Do not use an electric fan when it is over 95°F as it may do more harm than good. Take a cool shower to cool down the body, pull the curtains or blinds to shut out the sun and use air-conditioners to cool off.

Keep yourself cool

If you have to be outdoors, try to limit your outdoor activity to morning and evening hours and rest in shady areas. Avoid strenuous exercise as it takes a huge toll on your body. You can try to work out in shady areas or do a water workout. Remember to wear sunscreen with broad-spectrum or UVA/UVB protection to prevent sunburn and skin cancer. Here is an article about sunscreen.

Look for signs of heat-related illnesses

Heat-related illnesses are preventable and can be easily spotted. Heat cramps are one of the early signs. Look out for muscle pain or spasms and heavy sweating during intense exercise. Stop physical activity, drink water and wait for cramps to go away before continuing any physical activity. Heat exhaustion is slightly more severe. If you notice heavy sweating, pale skin, fast or weak pulse, nausea or vomiting, muscle cramps, weakness, dizziness, headache and fainting. Heatstroke if left untreated can have serious consequences. Therefore, it is vital to be treated immediately. They have similar symptoms of heat exhaustion with high body temperature, altered mental or behaviour (confusion), rapid breathing, flushed skin, headache and racing heart rate are common symptoms. The worst case is losing conscience or passing out. When you see someone who may be experiencing heatstroke, seek medical help at once. Get the person into the shade, remove excess clothing and cool the person. You can either cool it with water, fan misting with cool, place ice packs or cold wet towels on the person’s head, neck, armpits and groin.

Never leave pets and children alone in the car

Children and pets can die in a hot car in just a couple of minutes even with the windows rolled down. The vehicle is just like a greenhouse. For anyone who is vulnerable to extreme high temperature, a heatstroke can be developed within minutes.

Image is courtesy of ClimatePsychiatry.

Heat is a silent killer. The latest heat-related casualties are extremely alarming and a huge factor of that is climate change. This is something that cannot be solved immediately and more heat waves will be coming soon. It is essential to develop emergency plans and strategies to increase public awareness and build resilience. As an individual, try using the tips above to keep yourself and others safe. Stay cool, stay hydrated, stay safe and look out for each other.

Article Author: Michelle Lam

Article Editors: Stephanie Sahadeo, Valerie Shirobokov