Health Bar
From The Blockheads Wiki
A Blockhead's physical condition is displayed on its Health Bar.
Where Located
A health bar is displayed next to a Blockhead's reference icon on the left side of the screen. It's the upper bar with a red heart on its left.
A health bar is also displayed in the menu for eating food.
A health bar is also displayed on a Blockhead's full status window.
Decreasing
A Blockhead's health is reduced by physical injury (from falling or animal attack) or such environmental issues as eating too many chillies or running out of air.
Increasing
Eating something will usually restore health as well as relieving hunger.