..take Toughness. Spend some AP on Toughness-enhancements. Wear False life-items. Wear fortification. Dont start with minimum con.
After yet another encounter with a (level 8 with 44 hp this time) wizard dying constantly(who also bragged how his 15th-level sorc with 96 hp had no problems doing anything), I feel this need to be adressed some.
There is absolutely no excuse to not have these items/feats/enhancements, and dont blame the tank when you die ten times each quest.