During the summer, temperatures in many parts of the world are very high. This is something we all take for granted, but sometimes the heat can become extreme and last for several days, weeks, or even months.
This phenomenon is known as a heat wave , and it can have very serious consequences for health and life.
What is a heatwave?
A heat wave is an episode of abnormally high temperatures that lasts for several days or weeks and affects a significant portion of a country's geography . How many days or weeks? The truth is, there's no "official" definition, so it's difficult to say exactly how many.
In Spain, it is said that it is a heat wave when extremely high temperatures are recorded (taking the period 1971-2000 as a reference) in at least 10% of the meteorological stations for at least three days. But really this threshold can vary a lot depending on the country, for example:
- In the Netherlands It is considered a heat wave when temperatures above 5ºC are recorded for at least 25 days in De Bilt, which is a municipality belonging to the province of Utrecht (Holland).
- In the United States: if temperatures above 32,2ºC are recorded for 3 days or more.
When it occurs?
Most of the time, these incidents occur during the dog days of summer. The dog days are the hottest period of the year, running from July 15th to August 15th. Why are these considered the hottest days?
We tend to think of the first day of summer (June 21st in the Northern Hemisphere and December 21st in the Southern Hemisphere) as the hottest day, but this isn't always the case. The Earth, as we know, rotates on its axis, but it also tilts slightly. On the summer solstice , the sun's rays reach us more directly, but since the water and land have barely begun to absorb the heat, the temperature remains relatively stable.
Even so, as summer progresses, the ocean water , which until now has cooled the air, and the ground will have warmed up enough to begin a period of intense heat , which can vary in intensity depending on the region. For example, in Mediterranean climates, an extremely hot heat wave can occur during the dog days of summer. This phenomenon has been investigated and documented in several studies on climate change.
What consequences can a heat wave have?
Although they are natural phenomena and we have no choice but to try to adapt as best we can, if we do not take the necessary measures we could suffer their consequences, which are not few.
Forest fires
When a heat wave occurs during a drought, forests are at serious risk of catching fire. In 2003, fire destroyed more than 3.010 km² of forest in Portugal alone . These types of incidents are alarming, considering that heat waves can contribute to increasing the frequency and severity of wildfires.
Mortality
Children, the elderly, and those with underlying health conditions are the most vulnerable to heat waves. Following the example of the 2003 heat wave, more than 1000 deaths occurred in a single week , and more than 10.000 in France alone. This underscores the importance of adaptation and prevention in the face of these extreme events.
Health
When it's very hot, our mood can change considerably, especially if we're not used to it. But in extreme heat, if we don't take the proper precautions, we could suffer heatstroke or hyperthermia . Young children, the elderly, and those with illnesses or obesity are particularly at high risk. Understanding the difference between heatstroke and heat exhaustion is crucial to preventing these incidents.
Power consumption
During the hottest periods, our electricity consumption skyrockets. It's no surprise, as we need to cool down and turn on fans and/or air conditioning. However, this can pose a problem, since the increased consumption can lead to power outages , a growing concern in regions where heat waves are common, such as Spain , where related problems have been reported.
Most important heat waves
Heat wave in Europe, 2003
Chile, 2017
Between January 25th and 27th, Chile experienced one of its worst heat waves in recorded history. In the cities of Quillón and Cauquenes, temperatures approached 45°C, reaching 44,9°C and 44,5°C respectively . This event prompted reflection on the climatic conditions of that year and a comparison with other past heat waves.
India, 2015
In May, at the start of the dry season in India, extreme temperatures exceeding 47°C led to the deaths of more than 2.100 people by the 31st of the month. This event underscores the growing concern about heat waves in the context of climate change.
Europe, 2003
The 2003 heat wave was one of the most important for Europeans. Very high temperatures were recorded in southern Europe, with values ​​such as 47,8ºC in Denia (Alicante, Spain), or 39,8ºC in Paris (France).
14.802 people died between August 1 and 15, a figure that reflects the severity of the event.
Spain, 1994
During the last week of June and the first week of July, temperatures in Spain, especially in the Mediterranean region, were extremely high, such as those in Murcia (47,2°C), Alicante (41,4°C), Huelva (41,4°C), and Palma (Mallorca) (39,4°C). This event is remembered by many people who experienced these extreme temperatures.
Tips to cope as well as possible
When there is a heat wave, you have to do whatever it takes to cope with it. Here are a few tips that may help you:
- Stay hydrated: Do not wait until thirsty to drink water. With excess heat, fluids are lost rapidly, so it is essential that the body has a constant supply of water.
- Eat fresh food: As much as you like hot dishes, during the summer and, above all, during the heat period, avoid eating them.
- Put on sunscreenWhether you go to the beach or for a walk, human skin is very sensitive and can easily burn in the sun.
- Avoid going out in the middle of the day: during this time the rays arrive much straighter, so they have a greater impact on the ground and, also, on the body.
- Protect yourself from the sunWear light-colored clothing (light color reflects sunlight), wear sunglasses, and stay in the shade to avoid problems.
Heat waves are phenomena that can occur every year. It is essential to stay protected.