Warning: This video contains graphic images of burns caused by e-cigarettes.
KANSAS CITY, Mo. -- A warning for people using e-cigarettes: Hospital burn centers are seeing a growing number of people with severe burns from them.
It happens in a flash. In a video from a convenience store, you see a man's clothing catch fire and burn him. The battery in his e-cigarette had caught fire in his pant pocket.
A similar situation resulted in a burn on the leg for an area man. He's one of four people burned by e-cigarettes who've been treated at the University of Kansas Hospital's Burnett Burn Center this year.
"The burns have been really quite significant. They've been a result of overheating of these battery packs," Dr. Richard Korentager said.
That leads to fires or explosions. An article in the New England Journal of Medicine documented 15 cases at a Seattle hospital between last October and June of this year. More than half were burns to the legs or groin. Others were to the hands or face.
Dr. Korentager says his internet searches indicate many more e-cigarette burns are occurring than are being reported in medical literature.
"And there's in fact a number of law firms that are advertising looking for these kinds of injuries," he said.
The authors of the journal article call for increased regulation and design changes. Dr. Korentager says consumers should avoid buying e-cigarettes made in countries that don't have stringent manufacturing codes.
"That if you're buying one of these, you're not just buying on price," he said.
Lindsey Ryan says she carefully selected her e-cigarette.
"If mine were to overheat or malfunction in any way, it will automatically shut off," she said.
Still, she doesn't keep it in a pocket.
"I typically try to keep it in my purse or in my hand," Ryan said.
The doctor says if it starts to feel a little warm, get rid of it immediately.
The Food and Drug Administration recently started regulating e-cigarettes, but the authors say the prospects for battery regulation remain unclear.