Not to knock the 4 hikers, for they knew what to do and did save these mens' lives, but they appear not to have been very well prepared for the weather and location either (although this could be a function of the filter of the press). One pair of dry socks for 4 of them? One t-shirt, an overshirt and a sweater as extra clothing for 4 (and some of this may have been clothes they were wearing)! No hot drinks, stove or snacks (not to include a meal) at 4pm with at least a 2 hour walk in the cold back to transportation.
Again, I applaud them for their knowledge, well applied, but they were set up for needing rescue themselves if a problem had occurred for them and this was their level of preparation.
I would caution people not to read too much into the preparation of the 4 other hikers. The article in no way said that their supplies were limited to "one pair of dry socks", etc. It just says that’s what they gave him - the 400 lb man. I don't know about you but even in my wildest dreams could my spare clothing fit a guy that size. Again with hot drinks/sacks, etc. - the article left out identifying and detailing the number of items that the 4 other hikers were carrying except to generalize. "Tanaka and his three friends, who carried extra clothing, heat packs and food, were well-prepared and equipped, not only for their own plans but also for what happened, Schutts said." This story's focus is about the 2 brothers NOT the 4 hikers.
Ape Cave (I've hiked it 4yrs ago, btw) is a lava tube not a classic cave, about 2.4 miles long with the main entrance in the middle and at the head of the upper end of the tube (which is where the drama was). The lower end of the tube is basically a flat floor and is a piece of cake to walk. The upper end of the tube consists of fallen lava blocks. It's a fair bit of up and down scrambling and hard on your limbs which is why they were leery of backtracking through the tube. The tube is a pretty constant temperature in the mid-40's with high humidity. The trail from the upper entrance to the main entrance is less than 1.5 miles and is clearly marked in the milder months. But considering the heavy snow pack in the area it would be almost obscured. To hike the tube takes about 45 min for the lower end and about 2 hrs for the upper end. The entrance to the cave is expressly signed that the hikers ARE NOT to bring food stuffs OR hiking staffs OR leave any debris that may be left behind and damage the ecology of the cave OR bring pets OR have open flames. You are also not to defecate or urinate in the cave so facilities are provided above ground. You are NOT to touch the walls lest you damage the ecology of the cave slime.
When I hiked it (in the summer at the height of tourist season) my supplies consisted of my 10# day pack, spare clothing including long johns, gloves and head wear, jacket, snack and water, survival kit and FAK. I wore my boots, long light pants, 2 shirts, Tilley and carried a camera and 3 light sources with extra batteries. You can also rent lanterns as a light source (not sure about winter months). I carried stuff for me, not to rescue other people in the cave.