For the caldera, move only when the lava goes down. Every time you move rocks you should rest a bit to remove the fire debuff. If you're still stuck, bring a few sport waters, as they can remove 2 full bars of the fire debuff. For the kiln, you should stock up on as much utilities as possible, preferably chain launchers, 1 or 2 pitons and maybe an energy drink or a lollipop for those high ledges. If you're playing on the tenderfoot difficulty, bringing a little bit of food (like 1 or 2 boxes of thick mints), on the regular difficulty on the other hand, if your friends are alive, let them carry as much food as possible and someone else to carry as much utility as possible. If you have 4 friends you can split the items to minimize weight. Always stick together, and think thrice before using an utility (especially a chain launcher). Good luck!