Yes, it's probably not gonna help humans, unless some of your friends are gelatinous blobs with no circulatory or nervous system and with a lifespan measured in months.
Is also in the same group that has the only animals known to be potentially immortal. I'm not joking. This things exist. So the word "heal" here can mean different things than people expects. Imagine that as we grow older and decaying we could decide to grow a new genetic clone of "me" inside and reborn as happy babies, discarding our older shell. Some of this animals can do this to "heal" and the trick can be used an undefined amount of times. Those creatures are really ancient and have a few tricks on their sleeves.
Relevant for humans, as reef corals are related with jellyfishes and have free larvae that could respond in a similar way to temperature damage. Clytia could thrive when corals will die. This just another clue that some people is being more and more concerned by AMOC, even if it may be too late yet with all the warmongers ruining our last chances
Who knows, maybe we'll have organic suites for people or sealing membranes for mechanisms.
> We tend to think of the flower—or the jellyfish—as the organism, but these are actually reproductive units.
I'll never look at jellyfish the same.
Fun fact; where I grew up, we only had (at the time at least) two different types of jellyfish in the sea, blue and red ones. Easy to tell apart, one is "good", one is bad. However, now living in a very different place, suddenly what I learnt as a child is no longer right, there are tens of different species, some bad blue ones, some "less bad" red ones, and the easy "blue good, red bad" no longer works and it took a hard lesson to learn about this :)
Portuguese man o’ war is not a single organism at all but a siphonophore, a colony of many genetically identical but specialized individual organisms called zooids, all fused together and functionally dependent on each other.
Siphonophores are identical, except that they can be subdivided into units that are, much like organs, composed of multiple cells. Those units can be identified as evolutionary derivations of certain branches of the tree of life. This is more similar to your mitochondria, which are (like zooids) identifiable as having once been independent organisms, though unlike zooids your mitochondria are not genetically identical to you.
Actually, it bears pointing out that significant parts of you, like your blood, remain single-celled even though you're "multicellular".
But no. No such joy.