OK---the rules here are the same as the rules at home. Anthing that can spoil (and meat can spoil) can spend no more than 4 hours between 40 and 140 degrees before it can spoil.become unsafe. Once it's unsafe, boiling may or may not make it safe again. It certainly won't remove the flavor of spoilage.

So: if you freeze that beef, and carry it in a well insulated backpack for four hours, you should be fine. Two days? NOPE>

And just to clarify--to make a good stew you have to let it simmer for quite awhile. That uses a lot of fuel...