Overwatch 2

All event brawls are back as part of Overwatch Anniversary, although only one brawl per day (changes daily 7PM CT). Overwatch Anniversary ends June 11th, 2018.

This event will be available at (all times in CT):
5/23 7:00 PM thru 5/24 6:59 PM
5/29 7:00 PM thru 5/30 6:59 PM

Note: Only the week 1 and 2's schedule has been posted.

How do I unlock Cool As Ice?
In the arcade, select "Mei's Snowball Offensive"

You must kill 4 enemies without missing a shoot. You can die, which in turn means it doesn't have to be earned in a single round. However, it does have to be earned in a single game.

You will want to try and get the first kill relatively fast. Try to shoot anyone and don't be afraid to miss as you will still not have progress yet.
If you're on Ecopoint: Antarctica, at the start of the match climbing up the stairs and shooting across to the other doorway. There will usually be an enemy Mei trying to do the same thing.

For your other three shoots, wait until you see an enemy without ammo and follow them. Wait until they are reloading and then shoot them.

Additional Information about Mei's Snowball Offensive
You can look around when picking up snow without interruption
Snowballs arc
Both Ecopoint: Antarctica and Black Forest are available to play on

This achievement is earned in the Christmas Event, Mei's Snowball Offensive.

You need to get 4 kills without missing. You CAN be killed between shots. You DO NOT have to get the kills in the same round. You need to get them in the same game, however.

ParticleDuality suggests getting them to use their invincibility before shooting.