Frostbite and cold injury
Health telemetry with skin temperature against a personal baseline, and the offline medical guides for what to do next.
Activities · Multi-modal · Skill 5 · Extreme risk
Weeks from help. Nothing improvised.
Polar, desert, jungle, alpine and circumnavigation. These are the activities where the app stops being a convenience and starts being infrastructure: caches, rescue waypoints, extraction points and a comms plan that assumes every channel will fail at least once.
01 / By the numbers
2 wk–3moDurationLonger for a circumnavigation
−60°CPolar design caseFrostbite in minutes, rescue in weeks
5Layers auto-enabledHazards, caches, rescue waypoints, weather, extraction
4Comms channelsBecause one of them will not work
02 / What the app enables
Pick the activity. The map configures itself.
These layers switch on together, because they are the set this activity actually needs. You can change any of them; the point is that the default is not a blank topo map.
- Hazard zones
- Crevasse fields, sandstorm corridors, river hazards and political instability, by environment.
- Cache locations
- Pre-placed depots with contents and the date they were laid.
- Rescue waypoints
- Coordinates with the capability at each — not every point on a map can extract you.
- Extraction points
- Airstrips, river landings and vehicle-accessible ground, with season.
- Weather
- Multi-model, and for polar work the specific products that matter at latitude.
03 / Failure modes
The ways this actually goes wrong.
Every activity in NavTrax carries a documented failure-mode list, and each entry names the feature that addresses it. Not a disclaimer — a design input.
Crevasse fall or river crossing
Hazard layers per environment, and party positions over mesh where nothing else reaches.
Whiteout or sandstorm navigation error
Offline contours plus dead-reckoning and terrain matching when GPS degrades or is denied.
Stove or equipment failure
The kit list is versioned, redundancy is explicit, and the contingency plan names the fallback and the cache that holds it.
Psychological breakdown
On a two-month expedition this is a real failure mode. Sleep and stress proxies are on the leader dashboard, privacy-scoped.
Water contamination or depletion
Water planning is a routing constraint, and caches are tracked as consumable state rather than a note in a spreadsheet.
04 / Practice
What the app assumes you already do.
- Pre-placed caches
- Tracked in the app as depletable inventory with dates.
- Daily weather analysis
- Two models, downloaded over whatever channel is up.
- Rotating acclimatisation
- Per member, per baseline.
- Comms redundancy
- Cellular, mesh, satellite and a signed sneaker-net bundle.
05 / Curated kit
The gear list, scoped to this activity.
Pulled from the activity's own equipment profile and matched against the in-app store catalog. Nothing here is a generic recommendation.
ShelterExpedition tent4-season, guyed
Sleep−40°C systemPlus a vapor barrier
TravelSled or expedition packLoad-rated
SafetyCrevasse rescue kitPracticed, not just carried
CommsSatellite terminalPlus a mesh node per member
PowerSolar and lithiumCold-rated capacity
MedicalExpedition medical kitPlus offline guides and triage
NavigationRedundant GPS and compassOffline regions on two devices
06 / Under the hood
Keeping a party linked when a node dies
Infrastructure, not equipment.
Everything on this page is Pro. Health telemetry, custom workflows and industry modules are Elite.