Final answer:
A bonfire would cause more severe burns than a matchstick, a candle, or a lighter, due to the larger amount of wood being burnt and the greater total heat production.
Step-by-step explanation:
A boy scout will be burned more severely by a bonfire compared to a matchstick, a candle, or a lighter. This is because the amount of wood and, consequently, the total amount of produced heat in a bonfire is substantially greater than in a small flame like that of a matchstick or candle. Both matches and bonfires have wood that burns at about the same temperature per gram, as temperature is an intensive property depending on the material. However, the extensive property of the heat output, which depends on the total amount of material being burned, makes the bonfire more dangerous in terms of potential to cause severe burns due to the larger scale of burning material and heat production.