Lithium batteries have been proven to overheat and cause fires when not stored appropriately. This was noted by the FAA several years ago when they did not allow passengers to store lithium batteries from laptops in their checked luggage on airplanes.
Lithium batteries are used in many portable devices including vaping kits. Recently a paramedic on board an air medical aircraft suffered serious burns when lithium batteries in the flight suit pocket overheated and caught fire. These loose batteries were in a pocket along with keys and a sharpie.
As the pilot was preparing to depart, there was a bright flash reflected in the front canopy, screams in the back of the aircraft and smoke in the cabin. The Flight Nurse observed that the Paramedic was on fire. The Paramedic was removed from the aircraft and the flames were extinguished. The Paramedic confirmed that these batteries were personal property used in a vaping kit.
The fire was the result of a thermal runaway event involving these two loose spare batteries held in the pocket of the Paramedic’s flight suit. The Paramedic was later found to have sustained second and third degree burns to a moderate surface area of her body, mostly to her left arm and torso.
This is a strong reminder to seriously consider what is carried on board an aircraft. We are careful to secure equipment and ourselves on board. Remember to check your pockets. Do not carry loose lithium batteries. This is a danger on and off the aircraft.