You climb up a mountain and a cliff in search of fire, but all you find is charcoal. You can make fire with the charcoal, but you were hoping to find fire itself. All that climbing for nothing.
After crushing the charcoal, you decide to take advantage of your current location and lay out in the sun for a while to get a tan (たん). Instead of getting a tan though, you catch on fire. Oops.
Currently there are no similar looking kanji which exist in the WaniKani learning system