The fires are one type of puzzle. You must take them out to proceed along the map. The fires can be extinguished by finding and tapping water orbs. You need to find all fires connected to the water orb to be able to extinguish the fires. You won’t be able to interact with the water orb before you’ve found all the connected fires. Sometimes fires can be far away from the connected water orb so keep on exploring until you find them.