What do you mean the heat is good?

An auspicious omen, a sign of good luck.

"Having a good head" means starting some auspicious omens and signs of good luck. This is related to the emphasis on good luck in China culture. Everyone thinks that a good beginning can bring good results. Before an important event or ceremony, they will look for various ways to ensure good luck, such as choosing an auspicious day, wearing red clothes or doing other behaviors that are considered to bring good luck.