Reminds me of the TV Series "The Last of us" [0], which: "... is set decades after the collapse of society caused by a mass fungal infection that transforms its hosts into zombie-like creatures". Of course, minus the zombies.

[0]: https://en.wikipedia.org/wiki/The_Last_of_Us_(TV_series)

We are lucky that mass epidemics that plagued humans so far didn't affect the brain. Affections like rabies, that require individuals biting each other, and which are the inspirational source of all those zombie fantasies, do not count. That is an attack vector easy to spot and manage. The scary scenario is the one like with this Sporothrix Brasiliensis fungus, which can spread by merely "sneezing out the infectious yeast", and then remain potent (outside a host) for "up to 10 weeks", plus (the cherry on top) -- "developing the disease three years after" the infection event. Any kind of pandemic is scary by the sheer magnitude of its reach, but one that would affect the brain? That would be another level of scary.

In the opening scene a scientist argues once the ambient temperature of some region is 37°C we'll all get eaten by fungus. It will evolve to live at body temperature.

There are some precedents for this: hibernating bats lower their body temperature to that of a moldy environment, and are getting infected with a fungus which kills 90% of them in some cases [2]. Logic goes that raising the ambient temperature could be the same (with some evolution thrown in) as lowering our body temperature.

Is it credible? No idea, not that kind of scientist.

[1]: https://www.youtube.com/watch?v=OLNagvJHl3g

[2]: https://en.wikipedia.org/wiki/White-nose_syndrome

You mean the video games?