Fever can indeed kill. Raise the body temp a few degrees, no matter the cause, and things start going wrong very quickly. Google hyperthermia.

In fact, i cannot think of any disease that literally kills. Even with the big stuff like cancer or aids, it is always the symptoms that get you. They damage body systems and the decline of those systems (aka symptoms) eventually causes the cardiac arrest or internal bleeds that shut off nutrients to the brain. Those symptoms are just as lethal no matter thier cause. A massive fever that stops normal body chemistry, whether caused by flu or ebola, will kill you just the same.

I can confirm a fever can kill, saw and heard about it in SE Asia.

Hyperthermia differs from fever in that the body's temperature set point remains unchanged. https://en.wikipedia.org/wiki/Hyperthermia

Yes but the extra heat in the body causes the same cascade of chemical changes that will eventually kill. Initial treatment is different, to a point. If a fever is too high it will suddenly need the same treatment as hyperthermia: direct cooling.

Fevers do kill. It’s not common in western world where we have access to antibiotics but in developing world it’s more common.

I truly admire your confidence, even it I cannot have it myself.

Not a doctor: Isn’t fever (objectively, it seems) defined as a rise in body temperature? From what I’ve learned about protein denaturalization in high school, that doesn’t sound good if excessive.