way off topic!

Been looking at maps & needed a break, brother from another mother just retired from law enforcement and moved to a small rural town in western North Carolina so summer travel plans are being reconfigured

Ice crystals in jet fuel, makes one wonder what the gelling point is of avgas and why this is not a problem flying so high in freezing temperatures. All my years freezing on the flightline I never thought about this before.

Minot AFB at -40 in a snow storm uploading B52’s with special weapons and watching fuels pump em full of avgas while de overs struggled to keep em clean was a real bitch.

I know the SR71 used JP7 jet fuel and it was around -60 when being refueled from a KC 135 tanker and that the ST71 used the jet fuel as a coolant for its engines and systems

Ice crystals are separate from gelling. Ice is the water in the fuel and diesel will gel which is thickening of the fuel itself, basically the paraffins  solidifying. #1 diesel or kerosene has a much lower gel point. As I understand it, jet fuel is basically #1 fuel, or maybe further refined than that.
 I'm not sure about avgas, but the name suggests it's gasoline rather than kerosene. If so, I'm unaware if gas can gel, I've never heard of that happening. The only cold weather treatment I've heard of for gas (heet, etc.) is stuff that deals with the water contamination.