True, there are more things to consider with the 10 E’s. The way I look at it is one can survive 3 minutes without air, 3 hours of exposure to the elements without proper protection, 3 days without water and 3 weeks without food. With that philosophy good protective clothing for insulation and precipitation are one of the most important groups of all if one can keep breathing.
I certainly agree from experience to have a good headlamp on board. Many put navigation up at #1 and hard to disagree with that but getting lost is only one danger. Injuries that prevent walking out will really bring the protective clothing up to the life or death level.