Nonchalant

Calēre is Latin for "to be warm". In French it became "chaloir" and "non-chaloir" became nonchalant.

To be non-chalant then is to be not-warm.

Many have been called nonchalant.
None, chalant. That word does not exist.

Nonchalant is not cool, it is not-warm.
I prefer to be uncool.