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.
Jacksonville is the largest city by population in the U.S. state of Florida, and the largest city by area in the contiguous United States. It is the county seat of Duval County, with which the city government consolidated in 1968.