Last Updated Dec 15, 2015 10:39 AM EST
The number of injuries and fires associated with hoverboards has spiked 25 percent in recent days as U.S. safety officials try to determine what is causing one of the year's hottest holiday gift items to overheat.
The U.S. Consumer Product Safety Commission has received 50 reports of injuries and fires associated with the devices, up from 40 reports as of Dec. 10, spokeswoman Patty Davis told CBS MoneyWatch on Monday. The agency's latest count includes 39 emergency room-treated injuries with hoverboards that are fall and collision-related, up from 29 ER visits last Thursday. The hospital visits included 16 fractures, seven strains or sprains, five contusions or abrasions, two concussions and two additional organ injuries to the head. Also: three lacerations and four unspecified wrist, shoulder and ankle injuries. There have been at least 11 reports of fires in 10 states involving hoverboards this year, Davis added.
While the agency is not issuing a recall of any hoverboards until it determines what is causing them to overheat, it is advising consumers to use caution when purchasing or using them.
Consumers should not charge hoverboards overnight or when away from home, and should not bring the devices to a full charge before putting under a holiday tree. "Make sure you are there when charging and awake, and wait to charge until it is ready to be used," Davis advised.
The agency also advises consumers to purchase hoverboards from a reputable dealer, and check to ensure the batteries and chargers are certified by a national testing lab like Underwriters Laboratories.
Last week in Auburn, Washington, an employee from a mall kiosk that sells the boards was demonstrating how they work when another board caught fire, shoppers reportedly said. Another incident had a woman in Louisiana reportedly blaming the toy for a blaze that destroyed her home just days before Thanksgiving.
Riders of hoverboards should stay off streets to avoid collisions with vehicles, and wear a skateboard helmet and other protective gear, Davis said.
Meantime, some big retailers appear to be pulling back on the hoverboard craze. Overstock.com discontinued all hoverboard sales last week. And Amazon late last Friday stopped selling some versions of the device, according to Swagway, a leading manufacturer of hoverboards.
The consumer electronics company, based in South Bend, Ind., said in a statement on Monday that Amazon requested it and other hoverboard makers and marketers to provide "documentation demonstrating that all hoverboards you list are compliant with applicable safety standards, including UN 38.3 (battery), UL 1642 (battery), and UL 60950-1 (charger)'." Swagway added that it "already meets all those certifications and has already sent the requested information to Amazon."
Good luck transporting a hoverboard by air: All major U.S. airlines, including American, Delta, Southwest and United, have banned the devices in the past week, with Delta saying in a statement that the lithium-ion batteries that power many hoverboards are a potential problem, and often exceed the 160-watt-hour limit permitted aboard planes.
Early this month, British authorities said that of the hoverboards imported from outside the European Union, 88 percent of those tested had failed basic safety checks, the Guardian reported.