Salted-Caramel Semifreddo with Hot Fudge

In a bowl, beat whipping cream until soft peaks form, 2 to 3 minutes. In a second bowl, beat egg whites, adding sugar 1 tablespoon at a time, until fluffy and glossy, 3 to 4 minutes. In a microwave-safe bowl, stir together caramel sauce and salt; nuke until warm, 15 to 30 seconds. Gently fold whipped cream and caramel sauce into egg-white mixture; cover and freeze until solid, 4 to 6 hours. In a small saucepan over low heat, heat half-and-half, chocolate and corn syrup, stirring, until smooth and viscous, 2 to 3 minutes. Divide semifreddo and hot fudge among 6 bowls.