Meaning of the word "hot under the collar" in English

What does "hot under the collar" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

hot under the collar

US /hɑt ˈʌndər ðə ˈkɑlər/
UK /hɒt ˈʌndə ðə ˈkɒlə/
"hot under the collar" picture

Idiom

angry, annoyed, or embarrassed

Example:
He got all hot under the collar when I mentioned his mistake.
Don't get hot under the collar about such a small thing.