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
130 or above heat stroke highly likely with continued exposure
105 to 130 heat stroke likely with prolonged exposure
90 to 105 heat stroke possible with prolonged exposure