How heat threatens health | Science and health

In November, a report published by the British scientific journal The Lancet warned of the serious consequences of heat waves on human health.

The Lancet Countdown: Tracking Progress in Health and Climate Change is published annually since 2016.

The publication cites the problems caused by rising temperatures. like heat stress, heart failure and acute kidney damage due to dehydration.

It is also reported that last year, 157 million people worldwide were in a vulnerable situation due to heat waves, an increase of 18 million over 2016.

on average , each person was exposed to additional heat waves between 1 and 4 days between 2000 and 2017 compared to the 1986-2005 base.

These are problems that are also manifesting in Brazil as the summer approaches, whose official launch will take place on December 21 – even though it seems to have already begun in many regions from the country, which was already suffering from extreme heat.

After the start of the season, temperatures are expected to be even higher than those recorded in recent days.

According to Josefa Morgana Viturino de Almeida, chief meteorologist at the Center for Analysis and Weather Prediction of the National Meteorological Institute (INMET), the station should be between 0.4 and 0.6 degrees more than the average of last summer. with the exception of specific areas such as the extreme south of Brazil and the mountainous regions.

"Overall, the trend is to heat and to much above average rainfall.There is also a probability of El Niño establishment (abnormal warming of the waters of the equatorial Pacific Ocean) from December this year and early 2019, "says the expert.

Check below for the main health problems caused by high temperatures.

There are many ailments caused or aggravated by hot weather. Several of them, even, are cited in the Lancet document, such as heat stress (or heat stress).

As explained Mayara Floss of the Brazilian Society of Family and Community Medicine (SBMFC), one of the Brazilian organizations that participated in the development of the report, the human body feels difficult to adapt when it is exposed to high temperatures. promote change to defend oneself

"In this situation, the heat produced in the body is transferred to the surface of the skin by the circulatory system and by the internal tissue contact, for example, the dilation of the vessels to increase blood flow and eliminate perspiration for The body can also lose water, minerals and become dehydrated, "he says.

If the person remains exposed to the sun, the case tends to worsen to become sunstroke. "Our body can not reach 40 degrees, if that happens, the organs stop working, causing coma and even death," the specialist adds, pointing out that the danger is greater for children, the elderly, the elderly and the elderly. pregnant women, outside workers and people who already have health problems, such as respiratory, mental, kidney and cardiovascular diseases.

The important thing to avoid thermal stress and its aggravating factors is to stay well hydrated during ingestion of water and isotonic. avoid exposure to the sun between 10am and 4pm, avoid excessive alcohol and extreme exercises; Wear light and loose clothing and spend as much time as possible in cold environments.

Floss also recommends thinking more deeply about the planet: "People should plant trees, not deforest, change cars using public transit and bicycles, and make urban spaces greener".

Diseases Transmitting Diseases

Diseases such as dengue, chikungunya, zika and yellow fever, transmitted by mosquito vectors, are another source of concern in the summer.

Just to get an idea, according to a report published in The Lancet Countdown, the transmission capacity of the global dengue virus in 2016, given its influence on humidity, precipitation and temp (Aedes aegypti and 11.1% for the wild type Aedes albopictus ) compared to the previous year.

"Vector mosquitoes like warmth, the hotter they are, the better for them," says Enrique Barros, a family physician and member of SBMFC. "And it's not only that, the ecological problems (disordered urbanization, lack of sanitation and deforestation) are also totally related to this problem," he adds.

Among the individual measures taken to move away from the diseases mentioned are: taking a vaccine when there is this type of protection; do not drive in dangerous areas; use an insect repellent and clothing covering as much of the skin as possible; and install mosquito nets in rooms and mosquito nets in windows. At the same time, keep houses and streets clean, close garbage cans and leave no stagnant water – ideal habitat for insect breeding.

Vascular and Skin Problems

Although the Lancet Report does not specifically mention vascular problems as a consequence of rising temperatures worldwide, they are very common in Brazil, according to Breno Caiafa, president of the Brazilian Society of # 39; angiology. and vascular surgery of Rio de Janeiro (SBACV-RJ).

"The heat causing vasodilation, there is a circulation overload, especially in people with a history of varicose veins, thrombosis and venous insufficiency, which can cause edema (swelling) of the legs due to from the accumulation of fluid to the outside of the vessels, such as pain, feeling of heaviness, burning and itching, "reports the doctor.

High temperatures further increase the risk of allergies and erysipelas, infection of the dermis and subcutaneous tissue, caused by the proliferation of bacteria and may cause alterations of the lymphatic vessels (auxiliary vessels in drainage of the lower limbs).

Currently, Caiafa indicates the reinforcement of healthy habits, which include a balanced diet and preferably with little salt, good hydration, regular physical activity, do not stay long in the same position, a mbadage and lymphatic drainage, do not wear tight clothing and avoid alcohol.

"Anyone who has a vascular problem should also consult a vascular surgeon or an angiologist in the summer to know the number of guidelines and the regulation of drugs," adds the expert. The same is true for hypertensive patients because during the hottest season of the year blood pressure drops.

Abrão Cury, a cardiologist and general practitioner at HCor (Hospital do Coração) in São Paulo, encourages people to be more attentive to food on hot days, because high temperatures favor the proliferation of bacteria in certain products, such as as mayonnaise, sauces, condiments and seafood, which increases the risk of contamination.

The important thing is to ensure the origin and quality of what will be consumed, to properly store the products and to eliminate those that seem or feel strangely, especially on the beach.

Another concern related to hot days is skin cancer, a disease that, according to data from the Brazilian Society of Dermatology, accounts for a third of cancers diagnosed in Brazil.

"Summer is the period of greatest intensity of ultraviolet rays, which makes exposure to the sun more dangerous, especially for people with fair skin. "It's something punctual, it's not a lot of problem, but when the chances go up," he says.

Cury explains that the best way to protect oneself is to protect oneself from the sun, to avoid the hours of 10 to 16 hours and to use an appropriate sunscreen offering a high protection factor, emphasizing that it is fundamental comply with the manufacturer's specifications and submit a new application. within the time indicated.

Lancet Countdown Report

The Lancet Countdown: Tracking Progress in Health and Climate Change has been published since 2016 by the British scientific journal The Lancet.