I get it, but the heat index is not at fault. It will be (has been) caught along with decrying subjective interpretation vs. objective reality. You can easily make the point without the example, or with a different one. The problem with a broad stroke is that it pushes aside exceptions, whether or not they are valid. While in some cases this is a good idea, the correct course is not to just push on despite.
If it feels hotter than it is, that has real physiological consequences. If you feel hotter, you are very probably hotter. If perceived temperature is dangerously high, you are dangerously hot, even if true ambient temperature isn't. That is live-or-die reality, it doesn't get any clearer.