[Anchor]

No matter how hot it gets, many elderly people try to get by with just a single electric fan at home due to concerns over electricity bills.

They believe the breeze from an electric fan is cool enough, but does our body actually feel the same way? Reporter Jeong Banseok investigated.

[Reporter]

Electric fans are much more familiar to elderly people than air conditioners.

[Mr. Ha / Yeongdeungpo-gu, Seoul: Leaving the air conditioner running while you sleep is harmful anyway.]

[Mr. An / Yeongdeungpo-gu, Seoul: I live alone, so I just live with the fan on.]

During the heatwave in 2018, a study of 104 elderly residents in rural areas in South Korea showed that the very first thing they reached for to cope with the heat was not an air conditioner, but an electric fan.

Electricity costs were cited as the primary reason.

Just how effective is an electric fan in lowering body temperature?

Although mornings and evenings have become cooler, daytime highs in many places soared to 33°C to 34°C (91°F to 93°F) today (August 12).

Indoor temperatures are usually a bit higher than this and can rise up to 36°C (97°F).

A Canadian research team measured the core body temperature—meaning the temperature inside the body, not the skin—of 18 elderly people aged 65 and older for eight hours at 36°C (97°F).

The core body temperature rose to 38.3°C (101°F), and turning on an electric fan made little difference in the results.

This is because when the ambient temperature is high, an electric fan blows already heated surrounding air directly onto the body.

When the core body temperature reaches around 39°C (102°F), it can trigger life-threatening heatstroke symptoms along with organ dysfunction.

The research team analyzed that even when indoor temperatures merely exceed 33°C (91°F), electric fans fail to properly lower body temperature.

Of course, feeling the breeze from an electric fan creates a cooling sensation as sweat on the skin evaporates.

The Canadian research team warns that this is a "false sense of security."

They explain that individuals might fail to take necessary cooling measures because they feel a cool sensation on their skin while the inside of their body is not cooling down.

Elderly individuals, who secrete less sweat, experience a correspondingly smaller drop in internal body temperature and must exercise special caution.

[Kim Hojoong / Professor of Emergency Medicine at Soonchunhyang University Bucheon Hospital: You can think of the current heat as blowing winds like those in a desert. No matter how much the wind blows in a desert, it does not cool down the body; rather, it worsens the heat and dries out the body further. Therefore, a season has arrived where we can no longer get by with just an electric fan....]

The World Health Organization advises that setting an air conditioner to 27°C (81°F) while running an electric fan together can reduce electricity bills by up to 70% while making the environment feel about 4°C cooler.

(Photo: Cho Chang-hyun | Video by Jeong Yong-hwa | Graphics by Choi Haneul, Kim Yeji)