Wood is about to become an incredibly valuable commodity. People will need it daily for everything from keeping warm to cooking food. Cutting wood is more work than people think.
If you can fell a tree with something less powerful than a chainsaw you’re well on your way to having a resource worth trading for food. A small axe won’t cut it. You probably want a two man crosscut saw for felling the tree and a bucking saw for turning it into usable wood. This is a hard, sweaty job best performed by three people (the third keeps watch to make sure the tree isn’t about to fall in the wrong direction and also cycles in whenever one of the two sawing tire out.)
In addition to large firewood, people will also need kindling. Someone who doesn’t have a saw but does have patience can gather the kindling necessary to make fires. It won’t be quite as valuable as cutting down a tree, but selling kindling can still keep you fed.