ok here is a bit of history on the jet A verses jet B saga
JET 'B' is very close to military jp4 >airforce ole timers will sometimes argue the point , it is a wide 'cut ' fuel with a much lower freezing point -55C WITHOUT ADDITIVES than STRAIT JET A ( JET A-1) GETS CLOSE TO JET B)
1) It used to be the prefered avaition turbine fuel by northern Canadian operators both fixed wing and rotory . because of the being a naptha based fuel content which is more volitile >lower flash point = good in very cold country. as previous poster described but that property allows excellent starts in very cold Canadian climes.
JET B has a couple of down sides in the modern world
a) less mass so less btu's per liter or gallon 1.82 pounds per liter verses 1.85 pounds per liter for JET A1
b) since 2002the national defence department in canada, choose to go with one fuel type JET A >ERGO Imperial oil (esso ) the biggest refiner of jet b lost its biggest customer effectively dooming JET B to the history books.
c) due to that volitility ( lower flashpoint ) since 911 perceived as more a hazard
Parlkand fuels in alberta I belive still can provide Jet b in bulk however not sure what the contract volume or price would be these days.
IN CLOSING JET B IS A CLEANER FUEL the enviro weenies made a error in that ( put a jet a burning plane against a jet b plane and see which has the cleaner exhaust stream after 50 hours )
with -45 c temps and a cold soaked chopper or 200 kingair jet b will light off without killing the battery// jet a at that temp cross ones fingers hope your power to the pluggins didnt fail over night.
Fly safe !! winters nearly here omg wheres the jet b
check the engine tents extension cords /wing covers and all your winter kit your ass may depend on it at the most unexpected time