Wind chill above 10C


I have noticed that meteorological organisations such as the NWS and UKMO don’t calculate Wind Chill above 10C and the Heat index isn’t calculated below 27C. What I want to know is why is this? Surely the Human body still feels the cooling/warming effect of the wind between these temperatures. so why don’t they calculate these for the 17C between 10C-27C?

These values were intended as warnings of potentially hazardous conditions, between those temps it’s either too warm to worry about wind chill, or not hot enough to worry about heat effects.

there other index’s you can use that WD provides though
(like humidex, apparent temperature)