Take these ASAP on your toon. Level 1 for toughness (for more hit points), and lvl4+ for fortification. Do it. Trust me.
Most experienced players do. What is the point of taking all those meta feats if you are dead or the healer has to babysit your red bar. You might find yourself riding in someone's backpack for most of the quest without it.
Moderate (75%) or heavy fortification (100%) keeps you from being killed on a critical hit by a monster especially bosses. Many bosses can one shot kill a toon on a critical hit without fortification on. Light fortification is only 25% and not worth it. You can get moderate on a robe at lvl4. Heavy on a robe at lvl8. You might find yourself riding in someone's backpack for most of the quest without it.
Wear you best fortification... always.