Future temperatures challenge human survivability

India and Pakistan have recently suffered from a heat wave of up to 50 degrees Celsius, killing at least 90 people as well as destroying crops. South Asia, along with Africa, Australia, and the US Gulf Coast states, now face a potentially deadly combination of heat and humidity - something scientists couldn't have foreseen.

Canada was not spared either: in British Columbia, where 595 people died from heatstroke last summer, the village of Lytton recorded a new temperature record - 49.6 degrees Celsius - on June 29 before being leveled by fires. forest a day later, the heat also parched the ground, contributing to flooding in British Columbia a few months later.

According to Professor Blair Feltmate of the University of Waterloo: 'Temperature extremes will become more troublesome in the near future'. He is one of the authors of a report that identifies a future where heat could kill Canadians, especially residents of southern British Columbia, along the US border in the Prairies, southern Ontario and Quebec.

The people of India and Pakistan cope with the extreme heat

How does temperature affect the body?

With prolonged exposure to hot sun, people feel sluggish because the organs work harder to cool down as well as to keep them alive: the heart beats faster which helps push blood to the skin where it can be released. Heat and perspiration also contribute to cooling, but this mechanism becomes difficult as humidity increases.

In the case of heat stroke, the body begins to break down cells and damage organs.

Professor Stephen Cheung of Brock University explains: 'It's like cooking an egg. The reason an egg goes from a liquid to a solid is because the protein changes. If the body continues to heat up, unable to control its temperature, the protein in the cells will eventually have the same problem as egg protein."

Sitting in the shade and drinking water isn't enough to help people with heatstroke, he said, adding that it's important to cool them down quickly – ideally by immersing them in cold water.

Professor Michael Brauer of the University of British Columbia said that being too hot while sleeping also makes it more difficult for people to sleep, resulting in poor decision-making, vulnerability to injury, and affected mental health. So cooling the bedroom and the body to the point where you can sleep is very important.

A construction worker uses a large capacity fan for cooling in Canada

Fight with the heat

For those who intend to train the body to withstand high temperatures, Professor Cheung said this can be achieved to a certain extent. Our body's core temperature can adjust to higher levels over a period of 2 weeks of gradual exposure. But this is only a temporary solution to global warming, not solving the root of the problem.

'The biggest advantage humans have over other animals is our behavior. We make houses, air conditioners, clothes, etc. But everything - from increasing time spent indoors to increasing use of air conditioning - comes at a cost,' Professor Cheung said.

In addition, there are many people who cannot stay indoors or cool off, including some who have to work outdoors such as farmers or manual labor.

Professor Feltmate said that in the future, working hours will have to be changed so that the above workers avoid the hottest time of the day - for example, starting work at 5:30 am and ending at 1 pm.

He also notes that cities also need to be cooled: pay attention to the temperature factor when designing and improving architecture, plant more trees, paint houses white to reflect rather than absorb light. Residential areas need to be equipped with a backup power source to ensure that the air conditioner and fan continue to operate if there is a power failure.

People also need to plan for when some places like the Persian Gulf, South Asia, Central America and West Africa are too hot to live in. Cascade Tuholske, a researcher at Columbia University, warns that temperatures in the Bay Area are slowly surpassing human tolerance.