Bermuda may not see 100F on the thermometer but summer humidity can push the “feels like” temperature into the nineties and sometimes above 100 degrees. This combination of heat and humidity, rather than the air temperature alone, determines how difficult it is for the body to cool itself.

Around the world, periods of extreme heat are becoming more frequent and dangerous. More than 10,000 excess deaths were reported during the record-breaking heatwave that affected Western Europe in late June, while large parts of the United States have experienced dangerous heat-index readings beneath prolonged heat domes.

Bermuda’s climate is different but our humidity creates its own risks.

Your body cools itself mainly by sweating. As sweat evaporates, it carries heat away from your skin. When the air is already full of moisture, however, sweat cannot evaporate as effectively. Instead, it may simply run off the body without providing enough cooling.

Think of one of those sticky summer days when you step out of the shower and still cannot seem to dry off. The towel barely helps because the air is already saturated with moisture. A similar problem occurs when the body tries to cool itself through sweating.

This makes heat exhaustion and heat stroke more likely, even when the temperature displayed on the thermometer does not appear extreme.

The good news is that heat illness is largely preventable. Understanding your risk and taking a few practical precautions can help keep you safe and out of the Emergency Department.

Who is most at risk?

Older adults

As we age, the body becomes less efficient at adjusting to sudden temperature changes and releasing excess heat. Older adults may also feel less thirsty, even when they need fluids.

Chronic medical conditions, reduced mobility and the effects of several daily medicines may increase the risk further.

Infants and young children

Children heat up more quickly than adults and depend on those around them to keep them cool and hydrated.

Never leave a child or pet in a parked vehicle, even briefly. The temperature inside a vehicle can rise rapidly, even when the windows are partly open.

Pregnant women

Pregnancy places additional demands on the body and can make it more difficult to cope with extreme heat. Pregnant women should take extra care to remain cool and hydrated and should seek medical advice if they feel unwell.

People living with chronic medical conditions

Heart disease, high blood pressure, diabetes, kidney disease, respiratory illness and obesity can all make heat more difficult to tolerate.

These conditions are common in Bermuda, meaning more people may be vulnerable than they realise. Some mental health conditions, along with the medicines used to treat them, may also increase the risk.

Anyone working or exercising outdoors

Outdoor workers, gardeners, athletes and anyone performing strenuous activity generate additional body heat.

On a humid day, the body may not be able to release that heat quickly enough. Take regular breaks, seek shade and, where possible, move strenuous activities to the cooler morning or evening hours.

The medication connection

Many people are surprised to learn that some commonly used medicines can reduce the body’s ability to cope with hot weather.

The risk does not mean that the medicine is inappropriate or unsafe. It means that people taking certain medicines may need additional precautions and an individual plan for very hot days.

Medicines that may require extra care include:

Diuretics, sometimes called “water pills,” such as furosemide or hydrochlorothiazide. These medicines increase fluid loss and may contribute to dehydration, low blood pressure or changes in electrolytes.

Some blood-pressure and heart medicines, including beta blockers, Ace inhibitors, angiotensin receptor blockers and calcium channel blockers. Depending on the medicine, they may reduce thirst, lower blood pressure or affect the body’s ability to release heat.

Medicines with anticholinergic effects, including older antihistamines such as diphenhydramine, or Benadryl. These medicines may reduce sweating and interfere with temperature regulation.

Some psychiatric medicines, including lithium, certain antidepressants and antipsychotics. These may affect sweating, alertness or the body’s ability to regulate temperature. Dehydration can also increase the risk of lithium toxicity.

Stimulants, including amphetamine and methylphenidate. These medicines may increase body temperature.

Some pain medicines and anti-inflammatory medicines. Dehydration may increase the risk of kidney injury from non-steroidal anti-inflammatory drugs, such as ibuprofen and naproxen.

The most important message is this:

Never stop, reduce or change a prescribed medicine because of the heat without first speaking with your doctor or pharmacist.

Suddenly stopping some medicines can be more dangerous than the heat itself.

Instead, ask whether any of your medicines require extra caution during hot weather. People with heart failure, kidney disease or prescribed fluid restrictions should also ask how much they should drink on particularly hot days.

Medicines themselves must also be protected from heat. Avoid leaving them in a parked vehicle, near a sunny window or in another place that becomes excessively hot. Heat can damage some inhalers, reduce the effectiveness of insulin and affect certain medication-delivery devices.

When AC is not an option

Some Bermuda homes do not have AC, while others use it sparingly because of electricity costs. There are still practical ways to reduce heat exposure.

Close curtains and blinds on windows receiving direct sunlight.

Open windows during cooler morning and evening hours, then close the house before the hottest part of the day if the temperature outside is higher than it is indoors.

Use fans to circulate air when indoor temperatures remain below 90°F. At higher indoor temperatures, a fan alone may not provide safe cooling and may cause the body to gain heat.

Cool the body directly with a cool shower, bath or damp cloth placed on the neck, wrists or under the arms.

Wear lightweight, loose-fitting clothing.

Spend time in an air-conditioned public building, shop, library, church, community facility or the home of a friend or relative, even if only for a few hours.

Drink water regularly rather than waiting until you feel very thirsty.

Alcohol deserves special mention. It can contribute to dehydration and may make it harder to recognise that you are becoming overheated. When drinking alcohol outdoors, alternate alcoholic beverages with water and limit the amount consumed.

Just as importantly, check on others. Older neighbours, relatives living alone and anyone recovering from illness may not recognise the warning signs until they become seriously unwell.

Visitors are at risk, too

Visitors may arrive from cooler or drier climates and underestimate Bermuda’s humidity.

Hotels, guest houses and holiday-rental hosts can help by ensuring guests have access to drinking water, working AC or fans, and clear advice to stay hydrated and limit prolonged sun exposure during the hottest part of the day.

Visitors planning outdoor excursions should be encouraged to carry water, take breaks and avoid scheduling their most strenuous activities at midday.

A Cup Match reminder

With Cup Match approaching, many of us will spend longer than usual outdoors at the cricket field, on boats, at camps or attending family gatherings. Enjoy the celebrations, but plan for Bermuda’s heat and humidity, particularly during the hottest part of the day. The precautions outlined above are especially important when a full day of outdoor activity is combined with alcohol, limited shade and less attention to the body’s early warning signs.

Know the warning signs

Heat exhaustion may cause heavy sweating, cool or clammy skin, weakness, dizziness, headache, nausea, muscle cramps and unusual fatigue.

Move the person to a cooler place, loosen unnecessary clothing and cool the body with damp cloths, a cool shower or a fan if the surrounding temperature is not excessively high. Offer water if the person is fully alert and able to drink safely.

Seek medical advice if symptoms are severe, worsen or do not improve promptly.

Heatstroke is a life-threatening emergency.

Warning signs may include a very high body temperature, hot skin, confusion, slurred speech, unusual behaviour, collapse, loss of consciousness or seizures.

Call for emergency medical assistance immediately. Begin cooling the person while waiting for help but do not give fluids to anyone who is confused, having a seizure or unconscious.

The bottom line

Heat illness is one of the most preventable medical emergencies associated with summer weather.

Understanding your personal risk, knowing how your medicines may affect you, protecting medicines from excessive heat, staying hydrated and recognising the warning signs can prevent a hot day from becoming an emergency.

As periods of extreme heat become more common and Bermuda’s humidity continues to challenge the body’s ability to stay cool, a little preparation can make all the difference.

• Melissa Butler, PharmD, PhD, MBA, MPH, is a pharmacist and founder of The Evidence Space LLC, an independent health evidence consultancy based in Bermuda. This article is intended for general information only and should not replace advice from your healthcare professional