I realize that's the way the formula is set up.
It's just that the heat index is referencing something that doesn't exist, "a temperature" without a corresponding humidity level.
If you wish to say 85/60 feels like 90/30, I have no problem with that. But 85/60 doesn't feel like 90, it feels like 90/30.
Possibly I'm being over-precise, but they're taking a composite measure, temp/humidity, and expressing it as a single temp value. That's just wrong.
My you would like they expressed it as levels of oppressiveness.
Here today the heat is oppressive. And I am not just saying that because I live in AC.
I am actually a professional pet-sitter and dog walker. I am acclimatized to the heat by this time of the year, but my first thought this morning at 4am and 84F with 70% humidity was...oppressive. The chart calls it feeling like 90F...ah...no. This feels worse and is actually worse for you health-wise.
This situation actually makes your body work harder. Your heart will beat 15 beats more per minute in an effort to cool you. If you work outside like I do most days...even days like today are just plain nuts.
I actually issue my clients Dog Day Advisories via email. That way they know their dogs walks and outdoor play sessions are cut short. Potty breaks and then indoor work time & training instead. So far all of my clients have left a soda or gatoraid in the fridge for me. LOL