3 Rules for Healthy Fires

1. Ensure side flow
When combustion happens, surrounding air heats up and rises. Air rushes in from the sides to take its place, pushing equally from each direction. “This is why flames lick upward,” says Jason Forthofer, a mechanical engineer at the U.S. Forest Service’s Fire Lab in Montana. Leave ½ to ¾ inch of space between kindling sticks (more space for larger pieces).

2. Keep kindling dry
Use a slab of bark or a few green logs on the ground to protect your kindling from moisture.

3. Minimize the size
This isn’t a homecoming bonfire. “Keep it small, maybe only a foot high,” says survival expert Tom Brown, Jr. “Anything more is just a waste of resources and your energy. A large, open flame is hard to control and maintain.”