Survival Day Skill Challenge

In the new D&D Encounters module there appears an important term that has created some controversy. That term being "Survival Day". Now the module defines a survival day as "[those] expendable resources [that] account for food, water, proper clothing and other supplies. Each survival day allows a single character to travel in the dangerous wastes of Athas for one day without being subjected to starvation or thirst."
Now we all have to consume to survive. Though we don't usually have to think about it this way. But on Athas, life is gritty and very hard.
In order to get my players to start thinking along these lines I'm going to make obtaining a "Survival Day" a skill challenge by having them list and explain essential survival supplies. The following essentials are based on the US Army Survival Manual.

1. Water-the average person needs to drink aprox. 1 liter a day.
2. Food-eating and digestion consume water so drinking should take priority.
3. Loose clothing-as much skin should be covered as possible.
4. Fire-cooking food and warmth at night are imperative.
5. First aid-yes, even if you have a healer this is very important.
6. Food procurement-ranged weapons and snares are better.
7. Compass-not sure how to do this one, perhaps the PC's could explain how they navigate through the desert.
8. Salt-if you're sweating your going to need to replace your minerals.
9. Skin protection-what would the Dark Sun equiv. of Coppertone or Chapstick be.
10. Condom-now the manual says that you can use it for storing water. But, I was in the Navy and we used them for something else.

I plan on also having my Party role play how the might obtain these supplies. For example, animals that thrive in the wastelands may have a method for storing water in their bodies. Instead of searching for gold, they would search the vanquished for water. Now in the Encounters framework you can't spend too much time on one thing, but in this case I think its worth it.