We will see more and more fungi infecting mammals in the coming years. Mammals and birds evolved higher body temperatures in part to protect from fungal infections. As most fungi are dying above 37°C. But a high temperature summer is a selection pressure on any mushroom trying to survive, and hence might evolve to survive 40° summers and thus also survive in our bodies.

I really hope cordyceps is one of the last to do this step.

Not sure about that. Outside temperature above 37 were common in many highly populated areas, even before "high temperature summer" (e.g., India, Indonesia, most of Brazil, etc.). If there was an actual selection pressure, we would have seen its results by now.

One of the last, you say? The last of Us?