Below Tropical Night Standard of 25°C... "Mortality Risk Increases Starting at 22°C"

[Anchor]

The heat of the intense summer wave fails to cool down even at night. Typically, a tropical night is defined as when the nighttime lowest temperature does not drop below 25°C, but a new study has shown that the risk of mortality increases even at nighttime temperatures below this tropical night threshold.

Reporter Jeong Banseok has the details.

[Reporter]

85-year-old Ha, who lives alone in a single-room studio in Yeongdeungpo-gu, Seoul.

During the day, Ha stays at a senior center equipped with a heat relief shelter, returning home in the evening.

[Ha / Yeongdeungpo-gu, Seoul: I come here in the morning, have lunch, and since there is nothing else to do elsewhere, I go up to the second floor to catch some cool breeze and play janggi.]

Although Ha received support from the local government three years ago to install a window-type air conditioner, Ha gets through tropical nights using only a fan.

[Ha / Yeongdeungpo-gu, Seoul: The air conditioner broke, so it's a hassle to operate it by hand. I have to get up to turn it on, and get up to turn it off.]

It is past 7:00 PM.

Being a semi-basement space baked all day, the indoor temperature reaches 33°C.

Stepping outside the house, it actually feels cooler.

Measuring the actual temperature, it reads 31°C, which is 2°C lower than inside the house.

Without cooling or ventilation, indoor temperatures can rise more than 3°C higher than outside, meaning that even when the outside temperature is just 22°C, the indoors is effectively a tropical night.

An analysis of summer mortality data in the capital area from 2011 to 2017 by a Seoul National University research team showed that the risk of mortality increases by 4% when the lowest temperature is 22°C, rising up to 13% when it hits 25°C.

This means the risk of death increases even below the 25°C tropical night threshold.

Particularly for the elderly, caution is required as there are many cases where they do not turn on air conditioners even if they have them.

[Ahn / Yeongdeungpo-gu, Seoul: Even if it's hot, well. I just live alone. I just leave the door open and sleep. (Does the air conditioner work well?) I don't know because I haven't turned it on. Ever since my husband passed away, for 7 years? I haven't turned it on.]

[Kim Ho / Professor, Graduate School of Public Health, Seoul National University: Many elderly individuals do not run air conditioners due to concerns over electricity bills, and some fail to sense the heat due to declining physical functions. Even before a tropical night warning is issued, when temperatures are high, (steps should be taken) to ensure air conditioning can be used.]

Whether it is officially a tropical night or not, during sustained heatwaves, maintaining an appropriate indoor temperature through cooling or ventilation is essential.

(Photo: Yonhap News)
Reported by Jeong Banseok | Video by Kim Seung-tae | Video Editing by Choi Hye-ran | Graphics by Lee Jun-ho
※ Please note: This article was translated by AI and may contain errors.