Cave Temperature Layering Guide
Enter the cave's temperature, how long you'll be underground, how hard you'll be working, and whether the route is wet, and get a layering recommendation built to avoid both chill and sweat-soak.
Recommended layering
Base layer plus a light fleece or softshell mid layer.
How the recommendation is scored
The tool starts from the gap between a comfortable reference temperature and the cave's actual reading, then credits your activity level for the body heat it generates. A wet route and a longer trip both add points back, since both increase real heat loss and the practical risk of getting cold over time.
That combined score maps to a recommended layer count from one — a single wicking base layer for a mild, dry, high-exertion trip — up to five, for a cold, wet, long trip where staying warm takes real insulation and a full waterproof shell.
Frequently Asked Questions
Why is a cave's temperature so predictable?
Most caves sit at roughly the local mean annual surface temperature, because they're insulated from day-to-night and season-to-season swings by the rock above. That's why a cave feels cool in summer and comparatively mild in winter, and why the same cave gives a very consistent reading trip after trip.
How does activity level change the layering advice?
Moving generates body heat, so a hard-exertion trip — vertical rope work, tight crawling — needs less added insulation than sitting still or moving slowly in the same cave at the same temperature. The tool credits higher activity levels with a lower effective 'thermal deficit,' which can mean fewer recommended layers even in a cold system.
Why does a wet route push the recommendation up so much?
Wet skin and wet clothing lose heat far faster than dry skin in the same air temperature, because water conducts heat away from the body much more efficiently than air. A stream passage or a soaking crawl can turn a comfortable dry-cave temperature into a genuinely chilling one, which is why the wet-route option adds a meaningful penalty to the score.
What if the recommendation feels like overkill for a short, easy trip?
The floor is one base layer even in the mildest, shortest, most active scenario — caves are still cooler and often damper than most indoor spaces, and stopping to rest, wait for the group, or deal with an unplanned delay removes the body-heat credit that exertion provides. Treat the number as a sensible minimum, not a maximum.
Planning guidance only. Individual cold tolerance varies — bring more than the minimum if you run cold, and always carry a means to stay warm if a trip runs longer than planned.