Heat exhaustion is strongly related to the heat index, which is a measurement of how hot you feel when the effects of relative humidity and air temperature are combined. A relative humidity of 60% or more hampers sweat evaporation, which hinders your body's ability to cool itself.
Statistics (2015) Jacksonville International Airport (IATA: JAX, ICAO: KJAX, FAA LID: JAX) is a civil-military public airport 13 miles (21 km) north of downtown Jacksonville, in Duval County, Florida. It is owned and operated by the Jacksonville Aviation Authority.
Portland International Airport (IATA: PDX, ICAO: KPDX, FAA LID: PDX) is a joint civil-military airport and the largest airport in the U.S. state of Oregon, accounting for 90 percent of passenger travel and more than 95 percent of air cargo of the state.