This is the 14993rd most frequent Polish word.
rozgrzać
"Rozgrzać" means "to warm up" or "to heat."
Here, 'rozgrzać' means to increase the temperature of an object, namely soup.
Muszę rozgrzać zupę, bo jest zimna.
I need to heat up the soup because it is cold.
In this context, 'rozgrzać' refers to stimulating and preparing the body for activity by warm-up exercises.
Po biegu warto się rozgrzać, aby uniknąć kontuzji.
After running, it is worth warming up to avoid injuries.
Here, 'rozgrzać' implies the process of warming due to exposure to heat or sunlight.