What does picking up Winter Gifts in TF2 do?

team-fortress-2

There is an achievement for picking up 3 of them. Beyond that, they do nothing at all

Valve Gift Grab 2011 – TF2

Collect three gifts dropped by opponents.

Related

Do Dual Flurry and Duel Savagery apply to single attacks?
Will I have to purchase a cross-play game twice?
What's the best way to kill a floater in Dead Island?
Do workers only put in a percentage of work at the end of a turn if they used a movement point before starting?
Why is my dog so plump? Does he need to go on a diet?
Can Katarina's ultimate be stopped by roots?
What happens if I kill the shepherd's sheep?
What is the objective for League of Legends? Are there Quests?
Why does i = i + i give me 0?
Why does the C# compiler go mad on this nested LINQ query?
When installing packages with Yarn, what does "incorrect peer dependency" mean?
At what situation I can use Dask instead of Apache Spark? [closed]