Flares are every bit as dangerous as the person using them.
I've never heard of one going off by itself. If you're the kind of person who tosses lit cigarettes out of cars in summer, sets off illegal fireworks in your neighbor's dry field (upwind of his house), and likes to set wastebaskets of tissues on fire, then NO, you shouldn't use them.
Well, I've never had those arsonist yearnings.
But I do kind of get a kick out of lighting my charcoal chimney starter and watching the briquettes take off.
Seriously, I'm interested in these battery-powered devices. Just wondering if they're really as visible as the traditional flares.
Can't recall seeing anything in use that's brighter than a flare.