Go hot and cold - Idioms by The Free Dictionary
go hot and cold
go hot and cold experience sudden feelings of fear, embarrassment, or shock.
1973 Anthony Price October Men His wife had said…that she had gone ‘all hot and cold’ after nearly being run over.
go ˌhot and ˈcold (all ˈover) (informal) suddenly feel very worried, upset or frightened when you remember something very unpleasant: I go hot and cold all over when I think of that train accident. It was so terrible.