Ok in the continuing vein of taxing your creativity not mine for arcane components harvested from encounters not specifically identified as components you need to have an item in mind and describe what exactly you are using it for.  When making a ring of regeneration quenching the hot ring in trolls blood helps enchant the item.  The components will offer a reduction to the crafting cost based on a percentage of the xp value of the creature and the coolness of the description of the components. Against encumbrance each item will count as if it is taking up the same weight as its value in coins.

After some research it appears that losing a surge when you have none has various effects depending on the situation. If summoning you will lose HP according to your surge value. Starvation/thirst loses your level in hp.

So environmental effects (being out in the cold etc) will cost hp equal to your level. Any draining effects (from creatures) will cost your surge value. Note that in this instance failure in skill challenges that result in a loss of a surge will be treated like environmental effects and will represent the progression of the disease.

The DMG seems to indicate that a +2 bonus for withstanding environmental effects while resting is appropriate. This coupled with -2 penalty for the fever gives straight out end tests for withstanding the elements per travel period. Assistance of course is always appropriate though any assisting character will have to ride in the wagon for that travel period.