If you do wish to take any food which requires refrigeration, here is what I do - as I always have butter, semi-dried tom, salami, capsicum and cheese with me. This works particularly well if you are doing any walk-basecamp-walk-basecamp-walk style trips as I do with flyfishing trips.
1. The cloth 3-can (or for longer trips 6-can) silver lined coolers can be used - you simply need to keep the cloth wet, and the cooler in the shade.
2. At camp, if you are camped on wet ground, you place your food under the tent groundsheet. If camp is dry I lay about 2-3 litres of water under the groundsheet before placing the food under the tent & groudsheet. (food is normally at least in a silver bag, the cheap type you get from coles, etc.)
Both these methods work on the Coolgardie Cooler process - evaporation uses heat, and therefore sucks all heat from the surrounds.
I have used this method to keep grated pizza cheese cold & fluffy (so it never did get to melt) for up to 11 days in one of those oppressively hot type spells on the plateau. Often if I am staying at a hut for a few days - Nameless/Belcher, etc. I place the cooler in a shallow dish filled with water and hang it in the shade. Keeps it going well all day.
The wet cooler adds a little weight on the walk parts, but after a while you get to know just how little moisture is required on the cooler, in order to get you to your next camp, and still keep everything cool & fresh.
Works an absolute treat.