I only replenish electrolytes during strenuous physical activity or extreme heat when they may be rapidly lost. In a survival scenario physical exertion should be reduced to the lowest output needed. For a minimalist kit I would be inclined to say no. A larger unit or dedicated first aid kit may warrant inclusion. As an aside, I know with horses some owners pour so many electrolytes into their horses other vital micronutrients and vitamens are actually blocked from absortion.