Being used to Eastern European summers (think 100-110 degrees F, or ~40 degrees C), now that I moved to Northern Europe I pretty much shiver during summers, unless I choose to wear autumn attire...while everyone else wears shorts and Tshirts. I'm not really muscular, I'm very slim, I rarely (if ever) sweat, not even when I do cardio. My comfort temperature is >80F, or >27C - only then I can wear something like leggings and a Tshirt and feel good.