Are you ready?, Extreme high temperature warning | heatwave | high temperature

"How will humans adapt to high temperatures without air conditioning?"

This is Professor Zhang Chi, Deputy Director of the Asian Center for the Countdown of the Lancet, proposing his thoughts on the outbreak of various extreme events under high temperatures. The need for work, the dilemma of low income, and the risk of tight power supply make it difficult for air conditioning to become a lifelong companion for everyone to survive the scorching heat.

On June 19, 2023, local time, a woman wiped her sick husband's head at a hospital in Paria, Uttar Pradesh, India.

In just three days from June 17th to 18th, an extreme heat wave with a maximum temperature exceeding 40 degrees Celsius overwhelmed multiple hospitals in the two most populous states in northern India. According to incomplete statistics, over 170 people have died from heat related diseases in just a few days. And this number is still climbing.

This year, high temperatures have arrived unusually early in many parts of the world, including China. The latest progress chart of summer from China Weather Network shows that as of June 5th, most of southern China, the Beijing Tianjin Hebei region, as well as parts of Xinjiang, Shandong, Shanxi, and Shaanxi have entered a meteorological summer. Among the 21 municipalities directly under the central government and provincial capital cities that have already entered summer, 90% of them reported early this summer. In fact, according to big data from China Weather Network, summer in China has been coming earlier and earlier in the past fifty years.

The 2022 Lancet China Population Health and Climate Change Countdown Report, released in October 2022, shows that compared to the base period average from 1986 to 2005, the average number of heat wave days experienced by Chinese people in 2021 was 7.85, and the time for safe outdoor activities was relatively shortened by 48.2%; The potential labor time loss increased by 7.1%, and the national level heat related labor productivity loss resulted in related economic losses reaching 1.68% of the gross domestic product, exceeding China's defense expenditure budget that year.

According to a study published in 2022 by Professor Huang Cunrui, the leader of the first working group responsible for writing the above report and from the School of Public Health and Health at Tsinghua University, the total number of people exposed to at least one heat wave per year has increased from 480 million in 1979 to 1.04 billion in 2020 nationwide; Meanwhile, the proportion of the total population increased from 51.3% to 75%, and the land area experiencing heat wave events increased from 46.3% to 81.6%.

On June 18, 2023, the highest temperature in Beijing reached 35 degrees, and tourists in the Temple of Heaven Park took umbrellas to shade themselves.

Huang Cunrui told Pengpai News that extreme weather may become a new normal in the future, and the health risks and burdens caused by it will continue to intensify. However, people's attention to the fatal impact of extreme high temperatures brought about by climate change on health is still far from sufficient.

Danger to life under high temperatures, no one is left unattended

In the summer of 2003, a heatwave in Europe caused over 70000 deaths. Between June and August 2010, extreme heatwaves in Moscow and western Russia resulted in over 55000 deaths. The deadly crisis caused by high temperatures has begun to draw widespread attention worldwide.

In China, the 2020 Lancet Countdown Report on Population Health and Climate Change showed that heat wave exposure has led to more than double the number of heat wave related deaths in China over the past 20 years, with approximately 26800 deaths in 2019. In the same year, researchers from the Chinese Center for Disease Control and Prevention found that compared to non heat waves, the total risk of non accidental death related to heat waves increased by 15.7%, and the risk of cardiovascular and cerebrovascular death increased by 22.0%.

High temperature heat waves can have a comprehensive impact on human health. According to STAT of American Life Science Network, "from migraine to rosacea, lupus, rheumatoid arthritis, chronic obstructive pulmonary disease, asthma, chronic kidney disease, hypertension, type 2 diabetes, cardiovascular disease... Extreme hot weather will affect the body's temperature regulation system, water salt metabolism system, nervous system, urinary system, etc., resulting in a series of changes in physiological functions, overloading the body, increasing the burden of various chronic diseases, leading to the deterioration of basic diseases, and even death."

Professor Zhang Chi pointed out that the increase in mortality caused by heat waves is most pronounced among the elderly, but other groups are also at risk. According to the official website of the Centers for Disease Control and Prevention in the United States, people over 65 years old, infants and children, chronic disease patients, low-income groups, athletes, outdoor workers, and pregnant women are all vulnerable to high temperatures.

Professor Huang Cunrui also stated that the vulnerability and adaptability of people in different regions vary. In densely populated urban areas with many high-rise buildings, the elderly, children, and people with basic diseases such as cardiovascular and respiratory systems are more susceptible to the impact of high temperatures. For this reason, he called for special attention to vulnerable groups such as poverty, children, and the elderly, and targeted protective measures should be taken, and tailored response measures should be developed.

For the vulnerable population of the elderly, Professor Huang Cunrui encourages them to undergo regular health checks, measure indicators such as body temperature and blood pressure, detect potential health problems early, and take corresponding prevention and treatment measures. At the same time, it is recommended to avoid outdoor activities during high temperature periods and strong sunlight, and exercise such as walking and doing exercises in the morning, evening, or cloudy days.

On June 10, 2023, Shanghai experienced high temperatures, and elderly people took shelter from the scorching sun in the shadows of alleys.

In fact, no one can avoid the effects of high temperatures.

"If measures are not taken in a timely manner, our living conditions will be very worrisome when we become a vulnerable group." Professor Zhang Chi expressed her concern, "Especially our next generation will continue to live in a high-risk environment, not only in hot summers, but also in various extreme weather problems throughout the year."

"If the climate continues to deteriorate, by 2030 or 2050, people in some regions may face a situation where summer is not suitable for outdoor activities throughout the day. Now we can still choose to go out or not, and then we will have no choice," she added.

Early warning and medical care, the first and last line of defense

Meteorological warning is the first line of defense for high-temperature disaster prevention and reduction. According to the data released at the 2023 National Meteorological Work Conference, the current warning information release platform has successfully connected to more than 30 industries or departments such as water conservancy, agriculture, forestry, and health. The public coverage rate of meteorological disaster warning information has reached 97.67%.

In terms of meteorological health warning, as one of the first pilot units, the Jinan Center for Disease Control and Prevention, based on the health risk classification prediction model and population health protection guidelines for high-temperature heatwaves, took the lead in releasing health risk warning information for high-temperature heatwaves in 2021. However, Professor Huang Cunrui believes that the overall meteorological health risk warning work in China is still in its early stages.

He pointed out that adapting to climate change and protecting human health is a challenging and complex system engineering, which requires time and cycles to continuously improve and coordinate multiple departments to scientifically address the health risks brought about by climate change.

"In response to high temperatures, the meteorological department is responsible for issuing a high temperature warning, but for individuals, it is also related to health issues. This part is managed by the health department, and if extreme weather occurs, the emergency management department needs to go on site." Professor Zhang Chi explained the "complexity" of this project and the importance of strengthening cross departmental coordination.

According to the research results on health meteorological services in the 2022 Lancet Countdown to Population Health and Climate Change China Report, according to relevant news records, 21 out of 31 provinces have established cooperative relationships between meteorological departments and local health departments, which also means that there is still room for further improvement in inter departmental linkage and cooperation levels.

Professor Huang Cunrui also believes that the problem of data barriers in different departments is still widespread, that is, data resources from different departments are difficult to share in real time, there is a lack of close integration of practice and research, and a comprehensive cooperation and exchange mechanism has not yet been formed.

He suggested strengthening the linkage and data sharing among various departments, further developing and improving multiple time scale monitoring and prediction models and technologies for meteorological sensitive diseases, and gradually establishing a sound health meteorological risk warning and release system. The precise release of health meteorological risk warnings should also become a part of the resilience of the medical system.

On May 30, 2023, a yellow high temperature warning was issued for the weather forecast in Huangpu District, Guangzhou. The thermometer measured that the outdoor temperature had reached 42 ℃.

Compared to early warning and prevention, medical treatment when high temperatures occur has become the last line of defense to ensure people's life safety.

A study in the journal Environment and Health found that for every 1 ℃ increase in daily maximum temperature in spring and summer, the number of emergency cases of cardiovascular and cerebrovascular diseases increases by 17.3%, respectively. A study published by the National Kidney Foundation in the United States also showed a significant correlation between extreme heat exposure and an increase in emergency department visits related to kidney disease.

Liu Anlei, an emergency department doctor at Peking Union Medical College Hospital, said that there are still certain weak links in China's medical and health system in dealing with extreme heat weather. For example, a sudden increase in outpatient and inpatient numbers during hot weather may lead to a shortage of medical resources, and issues such as heatstroke prevention and cooling protection for medical staff need to be taken seriously.

In order to improve the climate resilience of the healthcare system, Dr. Liu Anlei suggests the following measures: firstly, to enhance the awareness and ability of medical staff to prevent heatstroke and cool down, and to increase their material security efforts. The second is to scientifically allocate medical resources and reasonably arrange medical services based on meteorological warning situations. The third is to strengthen the linkage and cooperation with other departments, build cross departmental and cross domain collaborative mechanisms, and jointly address the health risks brought by high-temperature weather.

The risk has already appeared on stage, but not standing in the spotlight

The threat of extreme high temperatures to life and health has not yet been fully recognized and valued by most people.

Dr. Liu Anlei pointed out that currently, most people have realized that hot weather may have an impact on their health, but their understanding of heat related diseases is not comprehensive enough, such as heat stroke, heatstroke, etc. People may only know one or a few of them.

To cope with the scorching heat, Dr. Liu Anlei gave advice on various aspects of clothing, food, housing, and transportation: wear loose, breathable, and lightweight clothes, and replace them with damp clothes in a timely manner; Drink plenty of water and avoid excessive consumption of beverages containing caffeine or alcohol; Use air conditioning or electric fans at home to prevent heatstroke and cool down, and prepare heatstroke prevention materials such as ice cubes and ice packs; Reduce outdoor activity time and choose to do it in the morning and evening.

At the same time, people also lack guidelines for dealing with related diseases, and "just endure it" is a common practice adopted by many people. Professor Zhang Chi pointed out that the physical discomfort caused by high temperatures in scenarios such as summer camps and military training for children or adolescents is often mistaken for only related to willpower rather than health issues. In fact, the temperature regulation and heat dissipation functions of minors are worse than those of adults, and they often cannot accurately express the symptoms and causes of their physical discomfort. Therefore, when children express discomfort, parents or guardians should immediately stop their outdoor activities in hot weather, and take appropriate cooling and fluid replacement. Often, it is too late for others to faint.

Professor Huang Cunrui further pointed out that improving the public's awareness of health risks under high temperatures requires multiple efforts. Firstly, the health sector needs to actively participate in the national strategic deployment process to address climate change. When taking climate action, it should advocate for prioritizing population health. Secondly, it is particularly important to carry out credible science popularization and education, such as providing health guidelines for extreme weather and matching self rescue measures. Finally, climate change education should become an integral part of the core curriculum in schools, incorporating the health hazards and policy actions of climate change into all stages of learning.

After increasing public awareness, there is still a gap waiting to be bridged from knowledge to action.

Dr. Liu Anlei pointed out that the current high-temperature warning system mainly focuses on the issuance and transmission of warning signals, but lacks specific action plans and measures to help the public cope with high-temperature weather. Professor Zhang Chi also stated that although the Meteorological Bureau may issue red or orange warnings for high temperatures, each individual still does not understand the risks they will face when going out at this temperature.

"For example, what does it mean for some industries before the arrival of high temperature or rainstorm? For example, for school, construction site, transportation and outdoor workers, should they continue with their original work arrangements? At present, there is no further specific guidance." Zhang Chi said.

On June 13, 2023, Xuchang, Henan Province, experienced continuous high temperatures as construction workers worked under the scorching sun.

For each individual with significant differences, the public also needs clear boundaries to provide decision-making basis for whether people can go out, how long to rest, and so on. Zhang Chi's team is developing a user-friendly mini program that can check the risks of outdoor activities in hot weather. It is expected to be available to the public by the end of June and early July.

At the same time, in addition to the lack of channels to obtain scientific guidelines, some vulnerable populations under high temperatures also face the problem of having no voice channels. Professor Zhang Chi calls for more vocal social groups to bring attention to vulnerable groups, especially those with no other choice who urgently need more protective measures. Taking the delivery man as an example, even though they know the risks of climate change, they still have to continue working for survival reasons.

At the same time, she also pointed out that the middle layer in the family is another key factor in solving problems outside of the social voice group. "In a family, it must be the power of the middle layer. Middle aged or young people can first obtain relevant knowledge. On the premise of taking care of themselves, they can go and help other family or friends." She said.

The scorching heat is approaching, and the health crisis under high temperatures urgently requires people's attention and action.