Your HP
100
Player maximum health.
Hunter base damage
~25
Four unarmoured hits kills you.
Scaling
Yes
Rises with day count, hunger and a dead campfire.
Armour is not about becoming unkillable. It is about buying one or two extra hits, which is the difference between escaping a bad encounter and dying in it. That is why the first helmet matters more than the first weapon upgrade.
The scaling problem
Hunter damage is reported to scale with day count and hunger and to spike when the campfire is out. Armour helps most in exactly the situations where those multipliers are already working against you.