#BTColumn – “Hot, hot, hot”

Disclaimer: The views and opinions expressed by the author(s) do not represent the official position of Barbados TODAY. By Dr. C.V.Alert  MB BS, DM.

Many years ago, when calypso singer Arrow, regarded as the first soca superstar from Montserrat, asked ‘de party people’ “How you feeling?” Their popular reply was “hot hot hot”. This monster hit even got adopted for the Cricket World Cup here in the Caribbean years later.  In fact, as the pace of Crop Over 2023 picks up, the response “Hot hot hot” describes the tempo of activities on the ground here as we approach the climax of this ‘carnival’ season.

But the chorus “hot hot hot” is also coming from a different quarter.  It is the response to climate change and global warming, where our planet is now hotter than it has ever been and apparently getting hotter.  Almost every week we are hearing new records for the hottest day ever, and the millions of people who are at risk for severe health outcomes when subjected to extreme heat conditions.

Exposure to high temperatures has wide-ranging effects on the body. One major effect is dehydration. If you don’t drink enough water to replace that lost through sweating and urination, the blood starts to thicken, making it more prone to clotting, which increases the risk of heart attacks and strokes. Drinks that are recommended to prevent dehydration include water, fruit-juices, electrolyte drinks, coconut water, and even diluted soft-drinks. But while these fluids are good, alcoholic beverages, energy drinks, drinks containing caffeine (e.g. black soft drinks, coffee) can actually aggravate dehydration, not prevent it.

Exposure to high temperatures often amplifies existing health problems, making older people and those with chronic conditions (NCDs) at particularly high risk. We have sufficient evidence that we are overstocked with persons who have one or more of the conditions obesity, diabetes mellitus, hypertension and dyslipidemia (mainly high cholesterol levels). The elderly and those who live alone are particularly vulnerable. Persons who work outdoors, in the agricultural and construction industries in particular, and even sports persons, who exert themselves outdoors, are at high risk.

The medical diagnoses associated with heat exposure range from heat cramps, heat exhaustion, heat syncope to heat stroke. When exposed to very hot conditions, an unprotected individual can rapidly move from (least serious) heat cramps to (most serious) heat stroke, the latter being a medical emergency that is associated with fatal outcomes, even in apparently healthy individuals.

Our young kids are also highly vulnerable, because they heat up more quickly, and they sweat less than adults, which makes it harder for them to cool down. Children also tend to run around outside more than adults, lack the judgment to limit their exertions and drink more fluids during spells of hot weather.

The body has several mechanisms to cool itself down in response to high temperatures. As the skin heats up, blood temperature also rises. This change is detected by an area of the brain called the hypothalamus, which also receives messages from temperature receptors in the skin. It responds by instructing tiny blood vessels in the skin to open up, bringing more blood to the body’s surface and allowing heat to radiate out. It also triggers sweating, which causes some of that excess body heat to dissipate when the sweat evaporates, cooling people down.

Heat can, and does, kill in several different ways. The first is dehydration which was explained earlier. Dehydration also means the heart must pump harder to ensure enough oxygen reaches other organs and tissues, placing it under extra strain. Both of these things are more dangerous in people with pre-existing conditions affecting the heart and blood vessels.

Excessive sweating also alters the balance of electrolytes in body fluids, which can affect nerve and muscle functioning. In extreme cases, this can result in seizures, breathing difficulties, or heart muscle spasms, which can be fatal.

As severe dehydration kicks in, the body tries to conserve water and people start to sweat less. Normal core body temperature is around 37°C, but if sweating ceases, or it becomes too hot and humid for its cooling function to work, body temperature starts to rise. Above a value around 42°C, proteins start to denature, resulting in organ failure and further nerve cell impairment.

High temperatures can also have other negative  effects on people’s health. For instance, drownings are a major cause of death during hot weather in some places, as many people head to beaches, pools or rivers to cool themselves down. Hot weather may disrupt crucial infrastructure such as water or energy supply, with knock-on consequences for the provision of clean drinking water and electricity.

It also has a detrimental impact on air quality, for example increasing levels of irritant gases like ozone, which can cause throat and eye irritation, and exacerbate existing respiratory or cardiovascular diseases.

Given that population exposure to heat is increasing as a result of climate change, it is important that people know how to keep themselves and their family members cool. Many of the factors leading to death are preventable. For example, children and elderly relatives being locked in vehicles is reported to be a major killer during heatwaves. Even though children and the elderly are at higher risk overall, there is plenty that can be done to reduce these risks.

To stay healthy, ensure that you drink lots of liquids if the days are very hot; do not wait until you are thirsty because that may be a late sign. Wear light clothing, and stay in the shade, even using umbrellas, as much as possible. Outdoor activities create the most high-risk situations related to these extreme environmental conditions. Try to avoid going outdoors and participating in strenuous activities, during the hottest parts of the day. If you have access to a pool, the sea or even an air-conditioned facility, use these as much as you can. And most of all, drink, drink, drink. Do not wait until you are thirsty.

While feeling “hot hot hot” is great when partying, when health is being considered, keeping cool must be the main priority.

Dr. C.V.Alert  MB BS, DM.

Family Physician. ]]>