There’s two types of “hot” just like there are two types of “cold”

How cold is the absolute or “actual” temperature but then they add in the wind chill factor because air moving over you cools you down quicker (or warms you up quicker but the difference in your body temp vs cold is greater than your body temp versus hot)

Now to see how hot it is there is again the actual temp and then what they call the “wet bulb thermometer test”. So they take two thermometers, one they wet a cloth that slips over the bulb of one of them and then basically whirl it a bit to see how much the water evaporates off the one to cool it down. This is how they see hot “hot” it feels. Your body cools off by sweating so the more humidity the harder to cool down and why you get soaked in sweat on humid days but dry as can be in the desert even if the actual temp is hotter.