Does that thing have a lid? If not, get or make one. You will use more fuel and the food will get cold while you wait for it to rehydrate (depending upon conditions) without a lid.
Refletix is the the way to go. I've been using a Refletix cozy with freezer bags in the Co. mts - 20/30s temps - for freeze dried eggs and bacon, mac and cheese.
Boil water, wait 10 min and a hot meal - great.