You hike into a very long and narrow canyon that runs north to south. You enter at the southern end of the canyon because the other three sides are bounded by steep cliffs. You hike all the way to the northern end. Lightning strikes at the southern entrance to the canyon and starts a brush fire. The wind is blowing strongly to the north so the fire is burning rapidly towards you. The brush completely fills the canyon so there is no way to hike out of the canyon to the south or hide in a cave or river bed (or anything like that) without getting severely burned. And the cliffs are too steep to climb. You are stuck in the canyon. It is impossible to escape from the canyon. You have nothing with you that can be of assistance: no shovel to dig a hole, no water to douse flames, nor any other tools or supplies. How can you avoid being burned?
