““I’m from Wisconsin, and I live in Tennessee,” said Alisa Hass, a professor of geography at Middle Tennessee State University. “Moving south is a huge shock to the body.” That’s because your body acclimatizes to the temperature range it’s used to — literally, your physiology changes. People accustomed to spending time outside in higher temperatures sweat more and have increased blood flow to the skin, two changes that can help the body offload excess heat. These are short-term effects and can go away if the person gets de-acclimatized, a process that helps explain why lower high temperatures in spring can produce the same levels of heat sickness as higher highs later in the summer, Sugg said.
But there’s long-term acclimatization, as well, with people used to living in hotter climates feeling more comfortable at higher temperatures — even if their health risks are actually larger. For example, in a comparison of outdoor workers in Mississippi and North Carolina, Sugg found that the Mississippi workers believed their jobs had lower heat risks but were also the ones experiencing more heat-strain events. Another study that compared the temperature and local perception of temperature across a bunch of European cities found that what people considered “neutral” in comfort corresponded pretty well with local temperature ranges and was, in fact, closer to the local maximum temperatures than the local mean.
There’s a whole host of studies showing that where you grew up and what you’re used to affects what temperatures you perceive as comfortable and safe. The reasons seem to range from physiological acclimatization to behavioral adaptations chosen based on the normal climate — like the fact that more than 80 percent of Tennessee households have central air conditioning, compared to 60 percent of Wisconsin households and less than 5 percent of homes in the U.K.”
https://fivethirtyeight.com/features/heat-index-temperature/