"It's Even More Dangerous in Summer"... Why Animals Are Becoming More Aggressive

Expansion of Health Damage from Heat Waves

Rise in Animal-Related Accidents

"Stress from High Temperatures...Triggers Aggressive Behavior"

As heat waves have moved beyond being temporary abnormal weather events to become recurring annual "health disasters," there are calls for a transformation of the public health system to adapt to climate change. In particular, as heat waves increase animal aggression, more than 70% of bee stings now occur during the summer months, and the risk of dog bites also rises with higher temperatures.

A strong sun is pouring down over the citizens walking in Insadong, Seoul. Photo by Jo Yongjun

On July 3, in a health discussion published in "Community Health and Disease" by the Korea Disease Control and Prevention Agency, Professor Kim Sungkyung of the Department of Preventive Medicine at Yonsei University Wonju College of Medicine stated, "Heat waves have become a recurring health disaster, not just exceptional weather events."

In 2024, South Korea recorded an average annual temperature of 14.5°C, the highest in 113 years of observation, and experienced 24.5 tropical nights per year—3.7 times the usual annual average. The year 2025 was the second hottest on record, with 29.7 days of heat waves, 2.7 times the normal average. Professor Kim explained that the fact that the past three years were the hottest on record demonstrates that heat waves have become a new normal.

Additionally, in 2025, South Korea entered a super-aged society, with 20.3% of its population aged 65 or older. This proportion is expected to rise to 30% by 2036 and exceed 40% by 2050. Professor Kim pointed out, "As rapid warming and aging are occurring simultaneously, the damage caused by heat waves could become even greater."

Heat Waves Affect Various Diseases and Mental Health

Health damage is also increasing. The number of heat-related illness cases rose from 2,818 in 2023 to 3,704 in 2024 and 4,460 in 2025. Estimated deaths increased from 32 in 2023 to 34 in 2024.

In 2024, 30.4% of heat-related illness cases involved people aged 65 or older, and 78.7% occurred outdoors. In 2025, the proportion of those 65 or older remained around 30%, and 79.2% of cases occurred outdoors, indicating that the elderly and people exposed to outdoor environments are most affected by heat waves.

The health impacts of heat waves go beyond heat-related illnesses. Domestic research on the health impacts of climate change has shown that heat waves and rising temperatures have negative effects on cardiovascular disease, renal diseases, and respiratory illnesses. In addition, worsening air quality, increased pollen exposure, changes in carriers of infectious diseases, and mental health problems caused by climate disasters are also identified as health impacts of climate change.

An outdoor air conditioning unit is installed on a building near Namdaemun Market in Jung-gu, Seoul. Photo by Dongju Yoon

"Animal Bites and Stings Increasing Due to Climate Change"

In particular, animal-related accidents have recently emerged as a health issue that should be noted alongside heat waves. According to the Korea Disease Control and Prevention Agency's Emergency Room Injury Patient In-depth Survey from 2020 to 2024, there were 3,664 cases of bee stings, 70.5% of which occurred between July and September. There were 726 cases of snake bites, with the highest incidence in September.

Overseas studies have also found a correlation between temperature and animal-related accidents. In a study analyzing 69,525 dog bite cases in eight U.S. cities, both higher temperatures and higher ozone concentrations were associated with increased rates of dog bites. Another study analyzing over 850,000 injury surveillance cases across China found that the risk of animal-related injuries increased by 1.57% for every 1°C rise in temperature.

Professor Kim stated, "It is known that stress responses from high temperature exposure, changes in sex hormones, and ozone influence dopamine function, which triggers aggressive behavior." He emphasized, "Animal bites and stings should not be seen as simple outdoor safety issues, but as public health problems that are highly sensitive to climate change."

He also stressed that heat wave countermeasures should not stop at individual behavioral guidelines. Professor Kim suggested that cities should increase shade, green spaces, water circulation areas, and access to cooling, and that, in the health sector, visit-based health management and preemptive contact systems should be strengthened for seniors living alone, people with chronic illnesses, people with disabilities, outdoor workers, and elderly people in rural and fishing communities.

He further added that it is necessary to expand the emergency room surveillance system to not only monitor heat-related illnesses, but also bee stings, snake bites, dog bites, and mosquito- and tick-borne infectious diseases, by linking this information with air quality data such as ozone, and to build region-specific risk maps.

Professor Kim stressed, "Climate change health measures are no longer supplementary policies; they must become the core of community health planning."

This content was produced with the assistance of AI translation services.