With people being called on to save power again this summer, electric fans are sure to remain popular as energy-efficient alternatives to air conditioners, but overheated consumers should take care not to overindulge in breezes generated by the spinning blades.
Electric fans use less power than air conditioners, and have seen a revival due to the threat of energy shortages that have plagued the nation since last year's disaster.
However, improper use of electric fans may cause health problems such as fatigue.
A 35-year-old Tokyo housewife experienced minor health issues last summer after being exposed to the wind from an electric fan for long hours.
The woman slept with the lower part of her body exposed to the breeze from a fan.
In the morning, her feet were cold and she felt fatigued, which lasted for about four hours.
Similarly, after an hourlong nap in front of the operating fan, she would wake up feeling thirsty, dizzy and with a poor appetite. "I plan to use a fan to save power again this year, but I need to use it more wisely," she said.
Fifty-three per cent of respondents in a survey of 1,000 people said they had experienced health problems they suspect were caused by electric fans.
The survey was conducted in May by Realfleet Co., a Tokyo-based company that sells amadana-brand home appliances.
Of the respondents who had experienced health problems, 60 per cent said they felt tired, 47 per cent said they experienced dry skin or dry throats, and 29 per cent reported feeling cold.
The survey also found that about two-thirds of the people surveyed who slept exposed to the breeze from an electric fan experienced some health problems, suggesting that their symptoms were caused by continuous exposure to operating electric fans.
Osamu Nishizaki, physician and director of Nishizaki Clinic in Chuo Ward, Tokyo, said, "Exposing yourself to the air from an electric fan for a long time can affect your body's heat-regulating mechanism and cause health problems."
Nishizaki said sweat evaporating on the skin lowers the skin's surface temperature, which then lowers the temperature of the internal organs via blood circulation.
Lower body temperature can cause poor appetite and fatigue.
According to a study by Panasonic Ecology Systems Co. in Kasugai, Aichi Prefecture, when the body was exposed to a one-meter-per-second breeze from a ceiling fan, the air temperature as felt by the skin dropped about 3 C.
"It's fine if you use an electric fan to cool down for 10 minutes or so after taking a bath," Nishizaki said. "But you shouldn't expose yourself directly to air from a fan for much longer than that."
Unpleasant symptoms decrease if the fan is directed at walls or the ceiling to aid air circulation.
High-performance fans that can generate natural-feeling wind are now available. They have sold well recently, but are a bit expensive--with price tags of 20,000 yen to 30,000 yen.
"I recommend types that can generate a subtle wind, like a gentle breeze," said Sonoko Toida, an expert on home appliances.
"They also make less noise and consume much less power than conventional fans. So they help save electricity, too."
In fact, older electric fans can cause accidents that are sometimes dangerous.
According to the National Institute of Technology and Evaluation, an independent administrative agency, electric fans caused 52 accidents last fiscal year. Some started fires, while in others the blades broke during operation.
In one extreme case, an electric fan that was more than 30 years old started a fire in a house that destroyed the home and severely burned the residents.
"If an old electric fan isn't working properly or causes a burning smell, don't use it," a spokesperson for the agency said.