Europe’s brutal summer: Should expats keep windows closed during extreme heat?

With “Spain is bracing itself for the next blast of heat as northern Europe stays cool…Southwest of Spain will see temperatures of 40C by Sunday.” (Bloomberg)

Greece’s wildfires may now be under control but officials say strong winds are still a threat. “Two weeks of wildfires fed by scorching temperatures, dry conditions and strong winds have caused chaos at the peak of the summer tourist season in Greece…The fires killed at least five people and burned almost 50,000 hectares (124,000 acres) of forest and vegetation, according to estimates by the Athens Observatory.” (The Guardian)

July was a month of “shattered temperature records, devastating wildfires in Greece and tragic loss of lives, people have been anxiously awaiting relief from intense heat conditions that gripped Europe…Scientists have been warning that as global average temperatures continue to rise, heatwaves in Europe are becoming more frequent and stronger.” (The Independent)

Airport strikes

The situation is worsened by inevitable summer airport strikes, making it harder for expats and tourists to escape the deadly heat. Across Europe, thousands of flights have already been delayed and cancelled due to industrial action. So, here are the latest strikes taking place at European airports during August.

High risk of heat-related fatalities for the elderly expats

So, what does this mean for expats who may have moved to Southern Europe for a better life and blissful retirement? As there is a significant population of British elderly expats living in Southern Europe. With Portugal, Spain, Italy, Greece, Bulgaria, France, Slovenia, Croatia and Malta considered as the best destinations for retired British expats for long life expectancy and sunshine. (Daily Express)

Well, they’re currently at high risk of heat-related fatalities. As “extreme heat is killing Europe’s elderly. Researchers estimate more than 61,000 people died in Europe from the record-breaking 2022 heatwaves – it could become the new normal.” (The Telegraph)

Elderly expats are at higher risk of heatstroke. As we age, our bodies become less efficient at regulating temperature, making seniors more susceptible to the effects of extreme heat. As older adults are more likely to suffer from heat-related illnesses such as heat exhaustion and heatstroke. (Centers for Disease Control and Prevention)

Heat-related fatalities are expected to rise amongst older adults, as human populations skew older as the Earth gets hotter. More intense, frequent and longer heat waves are driven by climate change. As it raises nighttime lows which prevents body temperatures from resetting when the sun sets. Climate change volatility “provokes in day-to-day highs can truncate the lives of older people with certain health conditions…It can be hard for even healthy older adults to tell when it’s too hot or if they’re dehydrated…Older bodies also hold more heat than younger ones when the temperature climbs.” (Harvard T.H. Chan School of Public Health)

We can already see this happening in Southern Europe, which has and will continue in the 25-30 degree range late at night this week onwards. Which is preventing the necessary nighttime lows from happening, as a result the elderly are not being given the chance to recover from the extreme daytime heat.

Southern Europe - predicted heat at 21:00 (07/08/23 - 14/08/23):

1. Madrid, Spain: 30°C (Spanish State Meteorological Agency)

2. Athens, Greece: 28°C (Hellenic National Meteorological Service)

3. Seville, Spain: 27°C (Spanish State Meteorological Agency)

4. Cagliari, Sardinia: 25°C (Italian Air Force National Meteorological Service)

5. Rome, Italy: 25°C (Italian Air Force National Meteorological Service)

6. Alicante, Spain: 27°C (Spanish State Meteorological Agency)

7. Brindisi, Italy: 26°C (Italian Air Force National Meteorological Service)

8. Barcelona, Spain: 25°C (Spanish State Meteorological Agency)

9. Palermo, Sicily: 25°C (Italian Air Force National Meteorological Service)

10. Naples, Italy: 24°C (Italian Air Force National Meteorological Service)

So, should expats keep the windows open or closed in extreme heat?

What does the research say?

Curated by the experts in safe home adaptations, Bathing Solutions

Proponents of keeping windows open argue that it allows for better ventilation and airflow, which can help dissipate heat and prevent indoor spaces from becoming stuffy and uncomfortable.

Doors closed: A 2016 study found that proper door closure can reduce the risk of heat-related health issues and contribute to energy conservation by reducing the need for air conditioning. (Lee et al., 2016)

On the other hand, advocates for keeping windows closed emphasise the importance of insulation against extreme heat. By keeping windows shut during the peak heat hours, indoor spaces can stay cooler without the need for air conditioning, whilst conserving energy.

Strategic ventilation: A 2017 study concluded that closed doors can act as a barrier to prevent heat gain, while strategic ventilation may be necessary to circulate air and maintain optimal indoor conditions. (Chen et al., 2017)

Based on growing up in Spain, Dr Ana Souto‘s philosophy is to close everything. “You can open the windows late in the evening and early in the morning – until 9am or so – when it’s cool, but otherwise keep them closed. My place is like a cave, but it works.” (The Guardian)

It’s best to find the right balance and there are exceptions to keeping windows closed fully. As “heat comes into the house in two ways: solar radiation from the sun, and hot air. We want to limit both, by closing the windows and curtains – but, if it reaches a point where the temperature inside the house is equal to that outside, then you should open the windows, keeping the curtains closed.” (Professor Amin Al-Habaibeh, The Guardian)

However, keeping your doors and windows closed doesn’t mean you shouldn’t properly ventilate your home. As high temperatures can strain the body's thermoregulatory system, increasing the risk of heat-related illnesses such as heat exhaustion and heatstroke. “Thermoregulation refers to how the body maintains its internal temperature. If your body temperature becomes too cold or hot, it may lead to severe symptoms and even death.” (Carissa Stephens and Kimberly Holland)

6 ways to ventilate and keep your home cool

So, here are six ways your home can be kept well ventilated and cool during extreme heat, as recommended by the experts in safe home adaptations, Bathing Solutions:

1. Strategic ventilation: Open windows on opposite sides of the home to encourage a cross breeze during the coolest hours (e.g. 6am-9am and 9pm-11pm) of the day.

2. Internal and external shade: Blinds, curtains on windows facing direct sunlight can block out the heat. External shading devices like awnings, shades, or exterior blinds can block direct sunlight and reduce the amount of heat that enters your living space.

3. Avoid heat-emitting white goods: Ovens, stovetops, dishwashers and dryers add unnecessary heat to your home and make it harder to keep cool during extreme heat. “We all know the phrase, 'it feels like an oven in here’...minimising the use of your oven and stove top and using smaller appliances instead will emit less heat and less energy.” (House Beautiful)

4. Strategic fans: Fans positioned on the sides of your home can be effective in pulling hot air out of your home, and wind blowing can maximise their effectiveness. If you have a windowless bathroom, a bathroom extractor fan can pull in warm air and excess moisture.

5. Door gaps: Ensuring that bathroom and kitchen doors aren’t tightly sealed against the frame allows for better airflow and promotes a well-ventilated space, reducing excessive moisture. A gap of at least half a centimetre would be ideal, although any amount of space is better than none. (Bathing Solutions)

6. Head for the AC: The World Health Organisation recommends spending at least 2 to 3 hours of each day in a cool place, such as an air-conditioned public building, e.g., shopping centres, libraries and supermarkets. If you have air conditioning, use it strategically. Set your thermostat to a comfortable temperature and avoid excessive cooling, as it can increase energy consumption.

Overall, keeping doors and windows closed during extreme heat can be a useful approach to reducing indoor temperatures, improving indoor air quality, and enhancing thermal comfort. However, It’s ideal to open windows during the early mornings and late evenings to boost airflow and ventilation.

To safeguard health during extreme heat, especially expats in Southern Europe - it’s critical to try a variety of methods, e.g., strategic ventilation, internal and external shade, fans and door gaps, otherwise head for the air conditioning if you don’t have it at home. There’s no harm in window shopping in a cool shopping centre or supermarket.

Disclaimer: This story is not intended to be official medical advice. For any concerns about your health, please contact your GP or the NHS 111 line.