FAA Guidelines?Since when did they have anything to do with an Automobile?I have used the MRE Heaters,Outside of my vehicle,& I've Never even thought about Lighting up the contents,Upon opening, for Retreival of food source!Are WE thinking Static Electricity for possible Ignition of Said,Minute amount of Hydrogen Gas? In that case,Go ahead & Have Cold Tea w/ Coddled Cream! I'll take my chances,Of which are Many,& Enjoy a Hot cup of VIA- Colombiano & Something to Nosh on,As well,Afterward,I'll use same used Heater bag to,Empty my Bladder into,So were Talking Multi-purpose for $3 bucks or less! I was gonna'say dual-purpose but realized,I could also Throw the bag at The Official from The FAA,of whom had the GALL,to walk thru a Blizzard,from his Cushy warm office at the Airport,Just to inform me,I'm Not abiding by FAA Guidelines!