When I'm out of the house, I have it at 84F since I don't want the air conditioner to run all of the time which cost money and shortens the unit lifetime. When inside, I lower it to 80F which is not bad since I only wear a swimsuit when inside and if it is 100+ F outside, it feels comfortable inside. You have to adjust to your environment, or it can get very expensive so in Summer, you dress down and even outside it is shorts, sandals and a short sleeve T-shirt. Do not try to have grass in your patio/lawn because the heat and very strong sun will kill it unless you constantly water it which is a bad idea during this drought, so I have a stone courtyard and cacti outside. At your place, 64F, I would be uncomfortable even with appropriate clothing because I'm not acclimated to it. In the winter it can get cold here, under 32F or 0C, but thankfully it doesn't last too long.