cold shower

Short definition from Wiktionary

Noun

1. 1
   A shower taken by a person in cold water; as taken for therapeutic reasons, or suggested as a remedy to calm sexual excitement.
2. 2
   Something unexpected and often unpleasant which makes one take stock or reconsider something; a sudden change or turn of events.
3. 3
   A chilly or unenthusiastic reaction to something or someone.