Extreme　heat　events　caused　by　climate　change　have　serious　adverse　effects　on　residents＇　health　in　many　coastal　metropolises　in　southeast　China.　Adaptive　capacity　(AC)　is　crucial　to　reduce　heat　vulnerability　in　the　human-environment　system.　However,　it　is　unclear　whether　changes　in　individual　characteristics　and　socioeconomic　conditions　likely　amplify　or　attenuate　the　impacts　of　residents＇　heat　adaptive　capacity　(HAC)　changes.　Moreover,　which　public　policies　can　be　implemented　by　the　authorities　to　improve　the　HAC　of　vulnerable　groups　remains　unknown.　We　conducted　a　questionnaire　survey　of　630　residents　of　Xiamen,　a　typical　coastal　metropolis,　in　2018.　The　effects　of　individual　and　household　characteristics,　and　government　actions　on　the　residents＇　HAC　were　examined　by　using　ordinal　logistic　regression　analysis.　Results　show　that　the　majority　(48.10%)　of　Xiamen　residents　had　a　＂medium＂　HAC　level,　followed　by　a　＂high＂　level　(37.14%).　On　Xiamen　Island,　residents　who　settled　locally　for　one-three　years　and　spent　less　than　one　hour　outdoors　might　report　weaker　HAC,　and　their　HAC　would　not　improve　with　increased　air　conditioning　units　in　household.　In　other　areas　of　Xiamen,　residents　with　more　rooms　in　their　households,　no　educational　experience,　and　building　areas　＜50　m(2)　might　report　better　HAC.　Further,　vulnerable　groups,　such　as　local　residents　and　outdoor　workers　on　Xiamen　Island,　people　lacking　educational　experience　and　renters　in　other　areas　of　Xiamen,　showed　better　AC　to　hot　weather　than　those　in　previous　studies.　Low-income　groups　should　be　given　more　attention　by　local　governments　and　community　groups　as　monthly　household　income　played　a　positive　role　in　improving　Xiamen　residents＇　HAC.　Rational　green　spaces　planning　and　cooling　services,　such　as　street　sprinkling　operations,　provided　by　municipal　departments　can　effectively　bring　benefits　to　Xiamen　residents.　Identification　of　basic　conditions　of　AC　has　significant　implications　for　practical　promoting　targeted　measures　or　policies　to　reduce　health　damages　and　livelihood　losses　of　urban　residents　during　extreme　heat　events.