Health

Engineers have Health that tracks how much damage they have taken. Health is divided into 10 visual segments, and if it reaches 0 the engineer will die. Respawning resets health to full, but the engineer's inventory will remain in a container at their death location.

Regeneration
When health is below 3 segments, and the engineer hasn't taken damage for 10 seconds, health will regenerate back up to 3 segments. The health bar will also turn red when below 3 segments.

Damage sources

 * Fall damage — Falling from a height of more than approximately 13 meters (3.25 foundation heights) causes damage. A fall of more than approximately 67 meters (16.75 foundation heights) will kill an engineer at full health. Fall damage can be prevented with a parachute or jetpack.
 * Alien attacks — Hostile aliens can damage the engineer with attacks, but will not do damage just from touching.
 * Rhino Aliens: Deal damage with a charge attack.
 * Spitters: Deal damage with fire projectiles.
 * Bugs: Deal damage by exploding on contact.
 * Poison — There are aliens and structures that spew poison around them. Poison deals damage once per second in increments of half a health segment.
 * Radiation — Certain areas of the world are affected by radiation, which depletes health rapidly in very tiny increments. The rate seems to vary in intensity within radiation zones.

Healing sources

 * Nut — Restores half a health segment.
 * Berry — Restores 1 health segment.
 * Mushroom — Restores 2 health segments.
 * Medical Inhaler — Restores 10 health segments.