Chilling is one of those idioms that cause trouble for ESL folk, as it has three very different meanings:
1. As a adjective, chilling means scary or worrying: "A chilling tale".
2. As a verb, chilling means to hang out, relax, and generally be calm and cool: "we were just chilln'."
3. In addition, chilling gets some use off of its root word, 'chill', meaning "to cool down": "I'm chilling the water in the fridge."
Technically, all three of these can be treated as present progressive forms of the word 'chill'... but not really. Using sense #1 as a simple verb is likely to sound weird. Most people do not say "it will chill you" except in certain stock phrases, e.g. "it will chill you to the bone". #2 can be conjugated as a normal verb, despite being slang; it is informal, and should be used with caution in formal and professional contexts. And the original meaning, #3, is just a tad archaic. Not to the point where you can't use it, but past the point where you can possibly guess at the 'proper' usage unless you have been raised hearing it; e.g., "my coffee chills" sounds weird, "my coffee is chilled" sounds okay, "my coffee is chilling" sound okay, but only okay if you have just put your coffee into the fridge to cool it down. Also, we don't say "chill it down", only "cool it down".
This mess makes it nearly impossible for a non-native English speaker to consistently use the word in a way that sounds 'right', and nearly impossible to explain what is right.