Why are there holes in the top of a football helmet?

Answer 1

There are two reasons for holes in a football helmet. Helmets have always had holes drilled in the crown area for ventilation. Body heat accumulates inside the helmet, especially during strenuous activity, and must be able to escape.

The newer modern helmet styles have larger and better placed ventilation holes designed to keep the player from overheating.

The second reason for holes in a helmet shell is for access to the air bladder fill points. Most modern football helmets incorporate air filled padding, which have one or more insertion points for a needle to add or release air to conform to the players head.