Hot Weather Intolerance
First time poster here. Is there a scientific or medical explanation as to why some people tolerate heat better than others? I've lived in Phoenix all my life and every year I seem to tolerate the summer heat less and now even when the temp is above 90 (which is not uncommon here for 5-6 months) my body becomes exhausted and craves a breeze. Some people who live here tell me the heat doesn't bother them at all and they don't mind working outside when it's 105 degrees or taking a walk in the morning when it's 90. They notice no difference in themselves. I notice between April-September here in Phoenix, I get tired more frequently/have lack of energy, feel the need to drink water constantly (even indoors), my mind goes into a funk, and I even feel warm with the a/c set at 78 degrees in the house. I feel like I want to stay indoors all the time and gonig to the mailbox feels like I'm entering an oven. I'm a 30 year old Caucasian male and it seems like in the last few years my body can't tolerate the intense heat and feel like I'm in an oven for 5 months out of the year. When I was younger, I didn't mind the heat as much and could even go without a/c in the car. Now, I can't drive my Honda because the a/c, despite having no malfunction and being full of freon, isn't cold enough for me when everyone else says it's cold to them, so I bought a 20 yr old Oldsmobile with an ice cold a/c that will freeze you out to drive in the summer. My Dad says it's too cold and has the temp in the middle on the dial while I always turn it way to the left (coldest possible temp). I feel great being in an office building or in a car where I assume the a/c is set at around 70, but at home when the a/c is at 78 on a 110 degree day I feel warm and need water. Sometimes when I walk in to the house, I feel like it's warmer inside, even though factually it's not. I went to San Diego by the coast this summer for a one week vacation and my body/brain instantly felt so much better. It was a natural 72-75 degrees in the apartment with no air conditioning and I felt great and hardly felt the need to drink water. My weight hasn't changed, and I don't have any known health problems. Any ideas what could be contributing to heat intolerance?