Heat, humidity too much to bear

DR C JAMES HOSPEDALES

“AH FIND it making real hot these days, boy/girl,” and “Even de nights hot, oui, de children cyah sleep good” are common refrains in recent weeks as TT and the rest of the world experiences record high temperatures.

Whether you call it global warming, global heating, or global boiling, there is no doubt that human-caused climate change is advancing with multiple impacts on people and the planet. Some call it "global weirding" because the weather patterns are so strange and unpredictable.

Climate change is caused by the excessive build-up of heat-trapping gases like carbon dioxide in the atmosphere from the burning of fossil fuels such as oil, gas and coal. Ninety per cent of that excess heat is stored in the oceans, so we not only have heatwaves on land, but ocean heatwaves which bleach coral reefs and kill marine life on a huge scale.

As a petro-state, this means that TT is part of the problem, as Prime Minister Rowley said when he returned from Glasgow in November 2021, having attended the Conference of the Parties on climate change; but that is another story.

God is not a Trini. The record heat we are experiencing, the devastating floods in many parts of the country earlier in the year, our eroding coastlines are all signs and symptoms that TT is being affected by climate change as part of a sick planet. More of this can be expected so people need to adapt.

The floods and droughts are not only occurring here but in the bread baskets of the world. The risk of global food shortages and markedly increased prices is very high if North America, Europe, China are simultaneously affected by drought/floods, for example. So, one of my first messages is to plant much food locally, plant #trees4food wherever you can. More on that another time.

With respect to the heat, recently I helped my brother and niece do some work for a few hours outdoors in the sun at their house in Diego Martin. I felt like I was going to die, despite drinking lots of water! The sweat was streaming off my body, and I started to feel bad. I had to stop and take a break and get into the shade.

I checked and saw the temperature was 33 Celsius – in the shade. In addition, the humidity was 85 per cent. When I looked up this combination of heat and humidity, that makes for a heat index of 510 C or 1240 Fahrenheit. I noted that various authorities listed a heat index of 510 C as a dangerous level for prolonged exposure.

A hot day can feel more uncomfortable when the humidity is high. It’s that sticky, suffocating feeling when there is excess moisture in the air. This makes you feel hotter because your body is unable to cool itself properly by sweating, which is why I had been sweating profusely in the situation mentioned above.

Heat index is a measurement of how hot it really feels outside. The heat index formula includes the air temperature and relative humidity. I remember once visiting a desert in California and the temperature was 430 C or 1100 F by mid-morning, but it did not feel unbearable as the humidity was very low, a situation of "dry heat."

As human-caused climate change advances, and the planet heats up, more water will evaporate into the atmosphere and increase the humidity and we will have more "wet-heat" periods, where both air temperature and humidity will be higher. So, people should pay attention not only to the air temperatures, but also to humidity. The Met Services should regularly report heat index. The population and the media need to take the heat issue more seriously.

Excess heat has important effects on our ability to think clearly, on mood and other aspects of our mental health and well-being. Heat stress has been linked to increased aggression and violence.

Hot temperatures reduce students’ ability to learn and perform at standardised tests. The education minister recently brushed off the situation by saying that principals and teachers are accustomed to the heat, which is true to a point, but we are not used to the record levels of heat and humidity we are now experiencing – and it is only going to get worse.

She likely made her comments from the comfort of an AC office and drives around in an AC car. She would have been wise to acknowledge that we are facing a new situation and to get some data together on what is actually being experienced in schools and take advice on practical measures to mitigate the increased heat.

Employees who work in hot conditions are not as productive and can suffer from dehydration, heat illness, kidney injury and other health problems, hence the importance of staying hydrated (drink enough so urine is pale yellow is one practical guide), taking breaks out of the direct sun. I soak my head frequently when I have to work outdoors to help stay cool.

Now, as has been pointed out by the Ministry of Health, some people are more vulnerable to the effects of high heat, such as older adults and people with certain conditions, such as heart disease. Certain medications can also make you more susceptible to heat intolerance. These include diuretics and beta blockers, commonly taken for high blood pressure and heart failure; some antihistamines and decongestants, commonly taken for allergies; and certain psychiatric medications. These pose issues with respect to heat.

What can be done practically? For older adults at higher risk, we can start by painting the roofs of the 100+ homes for the elderly in heat-reflective paint or just white paint, beginning with those in built-up city areas that usually get hotter because of all the concrete and buildings. If you work in a situation with only a galvanised metal roof above, advocate for insulation to be installed, and for the roof to be painted in heat-reflecting paint.

The hardware stores association, if we have one, can source and stock more heat-reflective paints. Although, I’ve been to many hardware stores and asked about heat-reflective paints and I invariably get a blank look. They need to get with the programme! Heat-reflective paints also reduce the demand for and costs of air conditioning.

Trees can be planted to shade the building or schoolroom or to help cool and beautify urban areas, which tend to build up more heat as asphalt roads and concrete buildings retain more heat than vegetation and grass. The temperature in the shade can be as much as five lifesaving degrees less than in the open. Trees can reduce a building’s AC requirements and reduce the costs of electricity.

Dr C James Hospedales is the founder of EarthMedic and EarthNurse Foundation for Planetary Health and a former director of the Caribbean Public Health Agency