Temperatures in Phoenix are around 102 degrees outside, and pool water temperature can be 80 degrees, but for some, it feels too cold to go swimming. Thermal perception is the temperature “felt” by the body, regardless of what the thermometer reads, said Robert Wang, an associate professor in Arizona State University’s School for Engineering of Matter, Transport and Energy. It varies from person to person, which explains why couples argue about where to set the thermostat.