Heating crystallized honey will cause it to re-absorb water. It can be as simple as running it under a hot water tap or putting it in some boiling water (microwave works too...but not so much in the bush).

I've heard that honey which has crystallized (cold temperatures can cause it to start) to a solid is no longer anti microbial by itself. When it goes hard it squeezes all the moisture out of itself as it crystallizes and the straight water can allow bugs to grow at the surface of the crystals.

A sealed package/tube might not be of any concern if you liquefied it in boiling water before using it but you might have issues if you used a little home-filled tub like I do. I really don't know.

I wonder if that kills the enzymes that help make it good for putting in/around wounds? If crystallization didn't, boiling it definitely could. That brings up another point. Buy organic (or at least non-pasteurized) honey to make sure it still has it's enzymes fully functional.