Once the core of the fire is mostly charcoal temperatures can climb up to 1100C. It doesn't have to be windy or even a large fire. Just need to be burning cha

Once the core of the fire is mostly charcoal temperatures can climb up to 1100C. It doesn't have to be windy or even a large fire. Just need to be burning charcoal and not evaporating water or burning off volatiles. The fires I have found aluminum globs in were long burning beach campfires and a bonfire to burn brush(big fire). The beach campfires were moderately sized but they certainly weren't bonfires built with 6-8 foot logs.