I started a new fortress, this one, I set the maximum world temperature to 1000, and tried to find a really hot area within it. And thus,
Fleshchamber. It was hot enough that the civilizations were marked "No Trade", although I seem to get traders anyway. And it has a lot of trees around for a place that's so hot.
Digging down in the beginning quickly was essential, not only to get everyone out of the sun, but also to get them away from the wagon, which decided to burst into flames upon arrival. I managed to rescue some plump helmets before they caught on fire, and was able to get down to the aquifer which provided me water, although I was able to get some alcohol made shortly after that, and started up a small farm with the plump helmets, keeping me alive.
Once I survived the start though it's really not too hard surviving here. I can go outside to build things, or chop down trees, I just have to make sure to limit the time any dwarf spends outside to short periods. Chopping down half a dozen trees a decent distance from the entrance without a break can leave a dwarf with minor injuries across their entire body, including internal and spinal injuries. But I don't have problem if I limit their exposure.
Immigrants who are unprepared though can have a bit of trouble. All of the immigrants who are wearing any bit of leather, will have that item spontaneously ignite, and burn away, and they end up dying in flames before they make it to my entrance. But about 1/3 or 1/4 of the immigrants, who only have cloth or silk on, manage to make it to my fortress before they suffer injuries from the sun.
Merchants run into the same problem, anyone carrying anything flammable tends to die a quick death. The Elves are the only ones who have made it here unscathed so far, since it's not hot enough to ignite wood directly. Although after, I should be able to go out and collect any metal or bones left over,if it's not too far away to run there and back before sun exposure burns my dwarves.
It also makes getting through the aquifer or dealing with extra water easy, all water that is hit by the sun immediately vaporizes into steam. I could expose the aquifer to the sky, and it vaporizes faster then it can come out. I also use that to have waterfalls that just come directly from the aquifer, and flow down to my sun shaft, where it gets vaporized into steam.
I like the high temperature map.
I can still do a lot of things outside at this temperature, but I have to be careful. It tends to ignite merchants most of the time though, but some immigrants can still make it through alive. Although some more work with specific heat and temperature of objects being remembered and not changing instantly would be useful, items tend to burst into flames immediately, or be fine indefinitely (or until the flammable object next to them catches them on fire) Creatures tend to survive the heat much better, only taking damage if they've been outside for a long time. I could try a hotter map, but if it gets hot enough to ignite cloth, it would be a bit hard to get new immigrants, but I could work with that.