Heat damage increased vs burn buildup increased

I understand what the first one does but whats “burn buildup increased” ? When is this one used in fight?
Thank you.

Does is mean that if I have a burning sword, every hit on the already burning enemy will do more damage ?

I don’t be believe so. My understanding is that buildup is different than damage.

For example lets say you do 100 damage with a hit and you have 30% increased burn buildup. That hit would do the 100 damage as expected; however the status buildup would be as if you have done 130 damage.

The payout from ailments occurs when the status bar is filled. This bar is influenced by the damage of the attack applying status as well as build up.

From the patch notes.

  • Status Effects reworked
    • Burn
      • Deals fire damage over time when the player hits an enemy with heat damage.
      • When this status effect is fully built-up, it deals even more damage.
    • Freeze
      • Enemies can become frozen upon being hit with cold damage.
      • Upon hitting a frozen enemy with physical damage, they will trigger the “shatter” effect, which deals massive damage to the enemy and ends the freeze effect.
    • Shock
      • Chain lightning effect triggers, dealing damage to the enemy and those around it.
    • Infection
      • Enemies affected by the plague status effect will take additional damage when they are infected.
      • The target will also have reduced healing.