Field Rest/Safe Rest
Field Rests (while adventuring) restore HP. Catch Breath: at least 10 minutes; expend Hit Dice one at a time, roll each and add your STR, and regain that many HP. Make Camp: at least 8 hours with food and sleep; take the maximum value for each Hit Die you expend instead of rolling, and add your STR to each as usual. A Safe Rest takes place in a safe location set by the GM (e.g. inn lodging—camping in the open wilderness or in a dungeon does not count). After a Safe Rest, heroes recover all HP, all Hit Dice, mana and other class-specific resources, and heal 1 Wound.
From Core Rules