If you use Petzl's popular MYO series of headlamps, check the batteries: Rechargeable batteries can cause the cable connecting the battery pack to the lamp to "spark, melt, or catch fire." Definitely not cool.
The U.S. Consumer Product Safety Commission and Petzl responded after logging 13 incidents of sparking and melting, along with two incidents of the lamp bursting into flames. Luckily, only one user reported a minor burn to the hand, while another experienced singed hair and perhaps an embarrassing Monday at work.
With 322,000 units in circulation, there's a lot of potential for accidental Ghost Riders popping up in the backcountry. Users are urged to stop using rechargeable batteries immediately and contact Petzl "to obtain a new warning label." I don't know about you, but I hope it looks like this.
— Ted Alvarez
Safety Alert: Petzl America Warns of Burn Hazard from Headlamps; Product Should Only Be Used with Non-Rechargeable Batteries (U.S. Consumer Products Safety Commission)