cold shower

noun3

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. •
   (figurative) Something unexpected and often unpleasant which makes one take stock or reconsider something; a sudden change or turn of events.

   • Ours is not a call to surrender – we aim to provide leaders with a realistic ‘cold shower’ of the state of the planet that is essential for planning to avoid a ghastly future. — 2021
3. •
   (figurative) A chilly or unenthusiastic reaction to something or someone.