In a recent thread I learned about the “Naked Flame Test”. I decided to try it in a local cave.
This cave is called Cueva Cucaracha and has been visited by many people. It’s joked that once you visit it you never go back. This cave has an estimate of over ½ million bats. It’s extremely hot and humid. It’s been measured at 95.5 degrees and 100% humidity. The cave has large borehole passage where all the bats are. A small dry stream passage runs along left wall and heads off to walking/stooping passage which is much cooler (80 degrees) for some distance then the old cave passages get bigger and bigger. It’s a significant cave system.
This time we brought some lighters and candles. We got to the cooler section in about 5 minutes and rested. We tried to light the lighters and couldn’t get them to light. Even though I was only breathing a bit heavy I was comfortable but freaked out that the lighters wouldn’t light. Another caver wasn’t “happy” either. I opted that we leave and upon turning around I missed the climb-up that lead out. I shouted to the group staying and they also decided to leave at that time. We had a CO2 meter but it only goes to 10,000ppm and pegged immediately upon entering the cave.
After leaving the cave a few of us decided to go back in to see when the candles would go out. We lit candles at the entrance and found about 40 meters into the cave the candles went out and the lighters would not light.
What we “know”, the O2 was <14.25%, the CO2 is >1%, the temp was >90, the humidity was 100%, Many people have visited this cave for many hours, bat’s thrive in this cave, guano covers everything.
If a lighter wont light do you get out right away?