Heat index calculations might not be a Communist plot, but they do not mean much. They aren’t reported regularly enough for anyone to have a sense of how hot some particular heat index value is. Relating heat index to ordinary temperature makes it seem like it means something, but who knows what that is?
A head index isn’t a temperature. There is something else factored in, so just relating it to a temperature leaves a degree of freedom hanging. It doesn’t satisfy to say, for instance, “The heat index is 110, and that means it feels like the temperature is 110 degrees,” because if the real temperature is 95 degrees, say, and you’re telling me that this 95 degrees doesn’t really feel like 95 degrees, then I guess I don’t know what 95 degrees feels like, and so how do I know what 110 degrees feels like?
I have become fond of dew point, however. For one thing, I know exactly what it signifies, technically. For another thing, I’ve looked for it in weather reporting for the last few years, enough to have a sense of what a particular dew point value feels like. I don’t try to think what it would feel like as a temperature; that’s not what it is. I appreciate the dew point as its own thing. When it comes to summer heat, I want to know the dew point first, before the temperature.