When Amalek came to fight Bnei Yisrael, the term used is "karcha baderech"- they happened upon you along the way. The word "keri" can mean by chance, and it can also mean coolness. If we view things in a cool, detached manner, Hashem will add cheimah-fury-to the keri, heating things up so that we will respond appropriately. Therefore, the idea of cheimah appears repeatedly in the megillah. We must take care not to "cool off" in our relationship with Hashem when his hand seems to be hidden, blaming things on chance like Amalek does.