freezer pack / ice block things

[ja9]

if i put a couple of these blocks in a freezer bag, along with frozen food, would the food stay frozen over a 3 hr journey?

Frozen enough to go straight in a freezer the other end, I would have thought. make sure the freezer bag isn't in direct sunlight on the way.

Last longer in a coolbox if you've got one, ja9 - better insulation.

thanks.