Sometimes it feels like the world is on fire.
Europe is in the grip of a severe heat wave. In Italy, this wave is being called ‘hell week’.
Temperatures above 50 degrees Celsius have been recorded in China and the United States. In hospitals in these countries, body bags filled with ice are being used to protect patients from heat. June was Britain’s hottest month on record.
Last year in 2022, the UK recorded temperatures above 40 degrees Celsius for the first time. That heat wave was blamed for 60,000 deaths across Europe.
So it’s no surprise that the United Nations has warned that we now live in an era of global warming.
“I think it’s really important to understand that it’s not just something that’s far away or in the future,” says Professor Lizzie Candon of the UK’s Met Office. We are actually seeing it happen now.
What effects will the changing climate have on our bodies and health?
I get sweaty in the heat. Nevertheless, I was invited to participate in the heat wave trade show.
Professor Damien Bailey of the University of South Wales now wants to show me a typical heat wave. So we are going to start this experiment with a temperature of 21 degrees Celsius.
The thermostat will be raised to 35 degrees and then finally taken to 40.3 degrees Celsius, the equivalent of Britain’s hottest day.
“You’re going to be sweating and your body’s physiology is going to change a lot,” Professor Damian Bailey warned me.
Professor Damian Bailey takes me into his atmospheric chamber. It is a room-sized scientific instrument that can control temperature, humidity, and oxygen levels.
I feel like I’m locked in an oven looking out.
The experiment starts at a pleasant temperature of exactly 21 degrees Celsius and then comes the instruction from Professor Damian Bailey to ‘take everything off.’
They didn’t convince me they were asking me to do this to get information about grinding by taking my weight.
Devices were then placed on me to track the temperature of my skin and internal organs, my heart rate and blood pressure.
A device was placed over my mouth to check the air coming out of my mouth and an ultrasound checked the blood flow to my brain through the arteries in my neck.
“Blood pressure is working well,” Professor Damian Bailey told me. Heart rate is working fine. At the moment, all the physical signals are telling me that you are in good health.
We did a short and quick brain test that involved memorizing a list of 30 words after which the temperature began to rise.
During this time my body had only one goal. I had to keep the core temperature of my heart, lungs, liver and other organs around 37 degrees Celsius.
“The thermostat in the brain, or the hypothalamus, is constantly monitoring the temperature and then sends signals to try to maintain it,” says Professor Damian Bailey.
We take a break at 35°C to make further measurements.
It’s getting hot here now. Things are not difficult now. I’m just relaxing in a chair – but I wouldn’t want to work or exercise in that environment.
Some changes in my body are already evident. My color has turned red. Professor Damien Bailey is also red he’s stuck here with me. The reason for the redness is because the blood vessels near the surface of my skin are opening so that my warm blood can easily release its heat into the air.
Besides, I’m sweating. It’s not dripping but my skin is glistening and as the sweat evaporates they cool me down.
Then we reach 40.3 degrees Celsius and now I start feeling hot.
“An extra five degrees Celsius doesn’t sound like a lot, but it’s actually physically very difficult,” says Professor Damian Bailey.
I’m glad we’re not getting warmer than that. When I wipe my forehead with my hand, it feels swollen. It’s time to repeat the test.
As I throw my sweat-soaked clothes on the floor, towel off, and climb back onto the weight machine, I’m shocked to discover that I’ve lost more than a third of a liter of water during the experiment.
My heart rate has increased significantly and is pumping an extra liter of blood per minute through my body compared to 21 degrees at 40 degrees Celsius.
The added stress on the heart is also the reason for the increase in deaths from heart attacks and strokes during rising temperatures.
Due to the loss of blood to the skin, the brain begins to lose it. My short-term memory is also impaired due to lack of blood flow.
But my body’s primary goal of keeping the core temperature around 37 degrees Celsius has been achieved.
“Your body does a very good job of defending this core temperature,” says Professor Bailey. But of course the data is showing that you’re not the same at 40 degrees as you were at 21 degrees, and that happened in less than an hour.”
Moisture factor
Only the temperature was changed in this experiment. The amount of air and water vapor i.e. humidity is another important factor to consider.
Hubas affects our body’s ability to cool down.
Just sweating is not enough. When sweat evaporates into the air, we feel cool.
When the air is already high in humidity, it becomes harder for sweat to evaporate.
Professor Damien Bailey puts the humidity at 50%, which is normal humidity in the UK. But a team from Pennsylvania State University in the US tested a group of healthy young adults at different temperatures and humidity levels. They were looking for the moment when the body’s core temperature begins to rise rapidly.
“Our core temperature starts to rise and that can lead to organ failure,” says researcher Rachel Cottle.
And this dangerous situation occurs when the temperature is low and the humidity is high.
The concern, says Rachel Cottle, is that heatwaves are not only becoming more frequent, longer-lasting and more intense, but also becoming more humid.
She says that last year India and Pakistan suffered from a severe heat wave where the temperature was alarming and the humidity was high.
“It’s definitely become a ‘now’ issue, not a future issue,” she says.
The human body is designed to function at a core temperature of about 37 degrees Celsius. If the temperature reaches 40 degrees Celsius, humans may faint.
High body temperature damages our body tissue. This includes the heart muscle and the brain. Going further it becomes fatal.
“Once the core temperature rises to around 41-42 degrees Celsius, we start to see really significant problems and if it’s not treated, the person will die of hyperthermia,” says Professor Damian Bailey. will.’
People’s ability to handle heat varies. But age and poor health can make us much more vulnerable. Temperatures that you enjoyed at one time may become dangerous at different stages of life.
“You’re going to leave the lab today with a smile on your face,” says Professor Bailey. All the statistics are telling me that you are up to the challenge and you have done a great job.
But old age, heart disease, lung disease, dementia and taking certain medications mean the body is already working harder to keep up and is less able to cope with the heat.
“Every day it’s a physical challenge for them (people like him),” says Professor Bailey. Now when extra heat and humidity are thrown at them, sometimes they are not up to the challenge.
How to deal with heat?
Many tips for dealing with the heat are obvious.
Stay in the shade, wear loose clothing, avoid alcohol, keep your home cool, avoid exercising during the hottest part of the day, and stay hydrated.
Another tip is to avoid ‘sunburn’, says Professor Damian Bailey. A mild sunburn can cause loss of ability to thermoregulate or sweat for up to two weeks.
But dealing with the heat is something we all have to get used to.