Q. I have seen an increasing number of people using their smartphones while in the sauna at my gym. I am concerned that the 125 degree-plus temperature in a room smaller than my walk-in closet will cause the battery in someone’s smartphone to explode. Could this happen?
A. Lithium-ion battery fires have been in the headlines for the past few years, and while many incidents have been attributed to manufacturing defects, bad design, punctures or electrical overcharging issues, some exact causes have not been pinpointed. These types of batteries are used by millions of portable gadgets every day, though, and those that receive proper care are generally safe and reliable.
However, manufacturers warn that exposure to high temperatures can have negative effects on the battery and the device it powers. Apple, Microsoft, Samsung and other companies advise keeping the smartphone and its battery out of extremely hot or cold temperatures. Most companies recommend using the device in an ambient temperature range of 32 degrees to 95 degrees Fahrenheit — with 62 degrees to 72 degrees being preferable.
While battery fires from smartphones in gym saunas have not been making the news, heat and portable electronics are typically not a good combination. Placing the phone in direct sunlight, near a heat source or in a parked car on a steamy summer day can diminish its battery performance, permanently damage the battery’s capacity or cause it to overheat. However, infrared saunas that heat the body instead of the air often encourage the use of electronic devices to pass the time.
Aside from battery-safety issues, there are other reasons to keep smartphones out of traditional gym saunas. For one, some patrons go in there to relax and get away from other people constantly interacting with their phones. Second, because pretty much every smartphone has a camera these days, privacy is a factor. If you are concerned about fires, phone fiddling or photos, you may want to speak to the manager or find a new gym.