metal or rock that is red-hot is so hot that it shines red:
The poker glowed red-hot in the fire.
Be careful with those plates - they're red-hot.
extremely active, exciting, or interesting:
a red-hot news story
The Braves have been red-hot in the last few games.
a red-hot feeling is very strong:
4 British English
the team or person who most people believe will win a competition