For many elderly people, electric fans are still more familiar than air conditioners.

[Ha Mo-si / Yeongdeungpo-gu, Seoul: Sleeping with the air conditioner on is already harmful anyway.]

[An Mo-si / Yeongdeungpo-gu, Seoul: I live alone, so I just live with the fan running.]

A 2018 survey of 104 elderly residents in rural areas during a heatwave showed that the first thing they reached for to cope with the heat was not an air conditioner, but a fan.

Electricity bills were cited as the primary reason.

Just how effective are fans at lowering body temperature?

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

Indoor temperatures are usually a bit higher than this, potentially rising up to 36°C (97°F).

A Canadian research team measured the core body temperature—meaning internal body temperature rather than skin temperature—of 18 seniors aged 65 and older at 36°C (97°F) for eight hours.

Their core body temperature rose to 38.3°C (100.9°F), and turning on a fan made little difference in the results.

This is because when ambient temperatures are high, a fan simply blows the already heated surrounding air onto the body.

When core body temperature reaches around 39°C (102.2°F), it can trigger life-threatening heatstroke symptoms along with organ damage.

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

Of course, feeling a fan's breeze creates a refreshing sensation as sweat on the skin evaporates.

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

They explain that because people only feel a cooling sensation on their skin while their internal body temperature remains uncooled, they may neglect necessary cooling measures.

Older adults, who produce less sweat, experience even less reduction in core body temperature and need to be especially careful.

[Kim Ho-jung / Professor of Emergency Medicine at Soonchunhyang University Bucheon Hospital: You can think of today's heat as what we call a wind blowing in the desert. No matter how much wind blows in the desert, it does not cool you down; instead, it aggravates the heat and dries out the body further. Therefore, a season has arrived where we can no longer survive on fans alone...]

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

"Relying only on a fan? It's dangerous," experts warn. (August 12, 2026, 8 News)

Reported by Jung Ban-seok | Produced by Bae Jun-hwi | Filmed by Cho Chang-hyun | Edited by Jung Yong-hwa | Design: Choi Ha-neul, Kim Ye-ji | Production: SBS Digital News