Scale Condition of person

In the component Ladybug_Outdoor Confort Calculator, the result ‘Condition of person’ has a scale between -3 to +3, Is there a regulation or something that allows me to understand where this scale is obtained from?

Assuming you are using the Legacy Outdoor Comfort Calculator, if you hover over the output you can see the explanation of the scale.

Thanks but I am using the Outdoor Comfort Calculator of Ladybug (include a link), not from legacy. And yes, I could have the explanation of the scale, but I am interested if there is a scientific source or regulation that describe an explanation of this scale, because I am working in a paper and one reviewer is asking for this scale.

Check this source:
Bröde, P., D. Fiala, K. Błażejczyk, I. Holmér, G. Jendritzky, B. Kampmann, B. Tinz and G. Havenith 2012: Deriving the operational procedure for the Universal Thermal Climate Index (UTCI). –International Journal of Biometeorology 56 (3): 481-494.

Thank you very much.