Metal Spider Temple
Here is a list of the curses inflicted as you explore. I wasn't exploring one tile at a time, so there is some error
~15 Tiles: Poison
~24 Tiles: Mana Burn
~39 Tiles: Corrosion
~44 Tiles: Corrosion
~49 Tiles: Corrosion
~55 Tiles: Weakening + Corrosion
~59 Tiles: Weakening + Corrosion
~64 Tiles: Weakening + Corrosion
~69 Tiles: Weakening + Corrosion + Warning of impending doom
~72 Tiles: Death
After further experimenting, I found that poison and mana burn get reapplied every time you reveal tile after first introducing these effects.
It is just barely possible to get the Fortitude Potion, Burn Salve, and Whupaz, allowing you to get the Whupaz with no permanent damage. If you can use the ENDISWAL glyph, then you can also get the healing potion. If you worship Jehora Jeheyu, then venturing into the spider temple just prior to purchasing chaos avatar is another way to get out unharmed.
LEMMISI and BLUDTUPOWA attract The Spider's attention just like normal exploration.
With foreknowledge and careful planning, you can squeeze a lot out of this dungeon. One possible scheme is:
1) Wait until you need some off-map exploration, then enter the temple and take exactly four steps south (eg reveal 12 tiles). Leave and do other things
2) The next time you are just a few points away from leveling, go ahead and expend all of your resources and renter the temple. We want to carefully blaze a trail that will give us access to the Fortitude Potion, Burn Salve, Whupaz, and altar, and to do so in a way that consolidates the maledictions so they can be easily treated.
3) Extend your trail one step south so that you are level with the Fortitude and Burn potions.
4) Walk directly west until you are standing on the Fortitude Potion.
5) Now walk east until you are standing on the Burn Salve.
6) Carefully light up all of the tiles surrounding the altar without actually touching the altar. This will let us revisit the altar later without having to get poisoned and mana burned again.
7) Blaze a trail to the Whupaz.
You don't have to leave the potions on the floor, I just left them there to make it easier to see what I did. You can use the Fortitude and Burn Potions to treat your corrosion and weakening, and then refill your resources by going back upstairs and leveling up. The altar is now safe to visit and you can invoke it whenever you want. Keep in mind that the altar doesn't just drain your health and mana, it also poisons and mana burns you again, making it awkward to exploit.
If you don't want the Essence Potion, you can just barely get the Fortitude Potion, Burn Salve, Translocation Scroll and Whupaz. A successful run should look like this:
Note that the altar is lit from the start. After exploring the temple in this manner, my test character died after revealing two more tiles (one at a time). This puts the death threshold at exactly 71 tiles.