This mod 'encourages' you to wear a helmet when you go mining by making you take damage!
What it do?
Makes the player take small amounts of damage if underground and not in skylight when not wearing a helmet.
Configurable rate at which the player takes damage.
Configurable Y level at which the damage starts.
Dimension Blacklist to disable damage in specific dimensions.
Depth Gauge item that when held within the inventory or hot-bar will display the current Y level in the top left! Y level will turn red when helmets are required!