Doctors Crossing Borders - between the elemental planes

[Prompt: A job that takes its practitioners to remote or faraway places]
In many of my worlds where the elemental planes are a thing, humoral medicine has some legitimacy, mainly in the magical realm. It's important for clerics and other magical healers to become intimately familiar with the four base elements. As such, a tradition has risen as a key part of magical doctors' medical training: Traversing the Elemental Plains.
The idea is simple. Deep into their training, typically during their master's studies, a student is expected to find a way into the Elemental Planes, and someone to accompany them. The student will journey into each of the four humoral realities, living there and learning, deeply, of their natures. The student should take notes on their findings of a given plane, and insights they gain about their own world and its inhabitants. Finally, traversers are expected to record and bring home at least one piece of new knowledge about each plane, which will be added to the Archive.
The task is simple, but not easy. There is no telling how long it will take, and absolutely no guarantee of success (read: survival). The Elemental Planes are famously dangerous places, hostile to anything incorporating the element opposite to each one. As most living beings incorporate all four* basic elements to some degree, this means the whole journey will be rife with peril. Students are strongly encouraged to do deep research on all of the planes before they set foot within them, to maximize their chances of survival (and get an idea for what knowledge already exists about each region).
If a student survives, successfully traverses all four planes and brings back valuable knowledge about all four, they are considered sufficiently versed in humoral knowledge, and permitted to move on to the next phase of their studies. Occasionally, the board will decide a student hasn't spent enough time in a given plane and send them back out. A lot of apprentices study planar knowledge to the point of paranoia, convinced they won't find knowledge good enough, but the secret is that the quality of the knowledge isn't that important to the Archive. It's more about the development of the student. Just don't tell the doctors that. They're plagued with impostor syndrome, confusion, and shorthand index cards enough as it is.
To the lucky 2/3 of medical students who survive the Elemental Ordeal, congratulations! Now you move on to your doctorate, in which you get to contribute even more new knowledge to the world. And you live in a world with monsters. You managed to survive exposure to the elements; getting spit samples from a dragon should be a piece of cake, right?

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*There is debate as to the presence of fire within most beings. Some argue this is the animating essence that makes mere moving matter into something more, while others say that is the domain of Spirit, Aether, or nothing at all. At the very least, most can grudgingly concede that the cleaving of molecules and magicules for energy is at least adjacent to the lighting of fire.