As the weather heats up, tensions rise. It's only natural. Yes, the sun can be a wonderful source of vitamin D, and it is true that we all feel a little better after 15 minutes sitting in the sun-- ‘sitting,’ being the operative word here. Ideally with a fun little cold beverage (or three) at hand. Having to live and walk and move and take public transportation in this heat is enough to drive anyone crazy. As summer unveils its highest temperatures, we unveil our lowest levels of tolerance for…