Each time a character suffers 1 or more points of stress damage, if his current stress damage total exceeds a multiple of his Wisdom score (e.g. 1 × his Wisdom score, 2 × his Wisdom score, etc.), he must make a Will save. The highest threshold exceeded by the total stress damage accumulated to date determines this save’s DC, as shown on Table 5.8: Stress Damage DCs. With failure, the character suffers the listed condition.
A critical hit with an attack that inflicts stress damage forces an immediate Will save, even if a threshold is not exceeded. This save’s DC is 16 (if no threshold has been exceeded) or the DC for the highest threshold exceeded +4.
At any time outside combat, stress damage wears off according to the character’s current stress condition, as shown on Table 5.8. Stress damage does not wear off during combat. When a character’s stress damage drops below a threshold, he loses the corresponding condition.
Example: Kevin has a Wisdom score of 12. He accumulated 10 points of stress damage before he reached the villain’s lair and his brush with a control panel fire spikes this total to 28 — more than twice his Wisdom score. Kevin must make a Will save (DC 16). He fails with a result of 12, gaining the shaken II condition. In his current state, Kevin heals 1 point of stress damage every 10 minutes.