Use of high altitude (8000 M) boots at lower altitudes (6500 M)

Question

On Himalayan climbs, good hiking boots (hard or flex soles) will suffice till base camp. Single boots like La Sportiva Nepal Extreme can suffice (in combination with gaiters) till maybe 6000 M peaks including the approach march to base camp. But they fall short at higher altitudes.

Are high altitude double boots, e.g. the Millet Everest Summit GTX, or the Scarpa Phantom 8000 or the La Sportiva Olympus Mons etc. usable on lower altitudes, like 6500 meters? Or will they be too hot?

The point being, suppose someone wants to acquire a single pair of mountaineering boots that will suffice across all altitudes - is this realistic?

Answer 1

An 8000m boot can certainly work for lower elevation objectives, but there will be drawbacks. There is nothing magically different about 8000m vs 6000m, other than this being a common terminology shorthand to describe the differences in conditions that one might anticipate.

1. Warmth. 8000m boots are heavily insulated and likely to be overly warm at lower elevations. However, this is highly objective and season/weather dependent. For example, this extra warmth might be highly appreciated for an ascent of Denali (6190m) or Mt. Vinson (4892m) in cold weather, but could be too hot and sweaty for a fair weather ascent of Aconcagua (6706m) or Kilimanjaro (5895m). This will certainly depend on how hot or cold you tend to run, along with your propensity to frostbite. Heck, I've even had friends use their 8000m boots for a winter ascent of the Grand Teton (4200m) during a particularly cold spell of -50F (-45C) weather, or use 6000m boots for ice cragging in the middle of winter.

2. Bulk & Weight. An 8000m boot will be heavier and bulkier than its 6000m counterpart. For example, the Scarpa Phantom 8000 weighs over 300g more per boot (30% more) than the Scarpa Phantom 6000 in the same size. That is an extra 300g per foot that will need to be lifted on every step, not to mention the the added bulk making precision footwork much more difficult. In addition, it is common to upsize 8000m boots by up to a full size in order to account for feet swelling at altitude and have additional room for warmth, which further exacerbates these issues.

In short, all design is compromise and the suitability of a 6000m or 8000m boot will highly depend on the specific objective and conditions. Fairer weather and more technical climbing will make a 6000m boot more suitable, while colder weather and easier climbing will make an 8000m boot more attractive. While these boots are all expensive, their cost is a small fraction of the total cost for an expedition to the greater ranges. Given that only your feet can take you there, it is almost always worth it to take the proper boot for the objective.