Is there an exercise index

There is a heat index that tells you how hot it feels when you combine humidity with temperature. There is a windchill index to tell you how cold it feels when you combine wind with temperature. Is there an index that combines activity level with temperature to tell you how hot or cold you feel?

For example, when I am sitting outside in 40F weather I am cold but if I am walking I do not feel cold anymore. So has anyone developed an equation to show how much perceived temperature goes up relative to activity level, ie activity at 30% intensity makes 35F weather feel like 54 but activity at 70% capacity makes 35F weather feel like 81?

This would be an equation of three variables in cold temperatures (temperature, wind and activity level) and three variables in high temperatures (temperature, humidity and activity level).

Not that I know of or have heard of. T
his should be a great opportunity for you to formulate one to account for all variables and quantify the activity variable.

How do you measure exercise intensity?

I don’t know for sure how to measure intensity. Perhaps by CO2 output or calories burned per hour relative to RMR (ie activity that burns calories at 3x your RMR is 30% intensity).