Temple of Ranma's Sailor Senshi Seifuku

how hot does the body have to be for war to instantly boil upon contact with the skin

But if we're talking about Ranma 1/2, we know that -- at the very least -- the body can become hot enough to turn rain drops into steam upon contact without real-life physics getting in the way. But that's a tiny amount of water; if Ranma had stuck his hand in a pot of water, how long it took for the water to boil would have been a better indicator of how hot Ranma's body had been.

Aside from that, I'd say it depends more on the amount of water involved than it does the heat of the body, since the time it takes for water to boil will ultimately be decided upon how much water comes into contact with the body, since the less water there is to heat the quicker it will come to a boil.

I'm not completely sure of which is hot - the body, or the water. But I am sure you will find this article instructive.

In chapter 319 Happosai returns from his underwear thievery with a very high fever. He wakes Ranma up with a splash of cold water, knocks her out, and then snuggles with her the whole night. The next morning, Ranma wakes up with a high fever too, having gotten the cold from Happosai. When Ranma tries to give his cold back to Happosai, he tells Ranma to turn into a girl so they can cuddle again. He pitches Ranma into the koi pond, but instead of changing into a girl like he usually does, his fever heats the water and keeps him from transforming. Ranma is sick, but overjoyed.

I think the issue is: if Ranma is hot enough to make the koi pond reach a furo-like temperature in a second or three, wouldn't heating the water that fast make it burst violently and/or flash-evaporate? Or something? I don't expect real physics to be relevant here, since it doesn't make any sense to me if the water is getting that hot that fast without continuing to get hotter than that to account for the speed in which it reached that furo-like temperature, but I'm also curious how hot someone/something would have to be in order for that much water to be heated to that temperature that fast.

If a liquid is poured onto something much hotter than its boiling point, the liquid in contact with the object will flash into vapor and push the main body of the liquid out of contact. You have probably seen this at home: heat up a frying pan, then pour a bit of water in. The water will break up into droplets which skitter about the pan for a surprisingly long time. The vapor keeps the heat from transferring rapidly to the liquid.

The same effect, though in a form much more like the question here, can also be seen in a blacksmith's shop. If you watch when the smith thrusts a piece of red-hot iron into cooling water, you will not see the iron -- you will see the steam surrounding the iron.

So it's not a good idea to heat Ranma to a temperature above 100 degrees Celsius, then throw hir in the koi pond.

Spokavriel wrote: Yeah... Um if you even hit 60C (140F) you're likely to see a person die from organ failures.

You've heard of cartoon physics? We're talking cartoon physiology here.