What temperature do Americans consider "hot" and "cold"?

Hawaii is tropical and Alaska extends above the Arctic Circle. We have a high number of different climates that our people might be accustomed to. But even if you look at just the contiguous 48, Miami is at 25 degrees latitude (further south than Cairo). People from Miami, Tucson, or El Paso probably start breaking out the sweaters at 70°F (or higher if it’s windy). For the northern latitudes it doesn’t compare well to Europe, because Europe is so warm and temperate compared to the rest of the world at those latitudes. But even though it regularly snows in NYC, it’s the same latitude as Rome. The people from NYC aren’t really saying they think 72°F is cold. Most people would consider it t-shirt weather. They are saying it’s a cold start to *summer* where summer weather is typically in the 80s and people expect it to start to feel, well, hot. Most of our cities are in places where managing excess heat in the summer can be a real problem and heat waves in the 90s (or 100s or even 110s) are a semi-regular occurrence. Most people here don’t wear *shorts* unless they start to feel uncomfortably hot. Would you say you feel uncomfortably hot at 64°F? Or just comfortable enough to wear whatever you want to without thinking too hard about the temp? Since only around 40% of San Francisco residents were raised in the area, their sense of it being too cold, even in the summer, is skewed by the climate of wherever they are from. Which is probably a place with hot summers. North Dakota regularly gets below 0°F in the winter (think Siberia) so I’m sure they’re wearing t-shirts when it gets to be 50°F.