This　paper　presents　an　experimental　investigation　of　thermal　behavior　of　flashing　spray　of　refrigerant　R134a.　A　high-speed　camera　up　to　1000　frames　per　second　is　used　to　visualize　the　shape　and　size　of　the　spray　and　an　infrared　thermograph　is　employed　to　visualize　the　temperature　variation　of　the　spray.　The　temperature　field　within　the　spray　is　measured　by　a　small　thermocouple　whose　position　can　be　systematically　adjusted　to　cover　the　entire　spray.　The　high-speed　photo　images　of　sprays　revealed　an　explosive　spray　formation　near　the　exit　of　nozzle　and　the　formation　of　a　hot　core　region　near　the　nozzle.　The　measurements　found　that　the　hot　core　region　was　quickly　dissipated,　followed　by　a　cold　region　of　almost　uniform　temperature　that　is　far　below　the　saturation　point　of　R134a　at　the　ambient　pressure.　The　measurements　provide　detailed　quantitative　information　of　both　radial　and　axial　temperature　distributions　of　droplets　within　the　spray.　These　results　provide　insight　into　the　formation　of　flashing　spray　of　volatile　liquids.　Copyright　©　2011　by　ASME.