You've probably already imagined it, it's now possible. In Fortnite Chapter 2 Season 2, you'll be able to help your allies in trouble by throwing healing items at them. To do so, simply find any healing item and press the corresponding key to aim (e.g. right-click on PC). Then press your shoot key to catapult your item to the desired location.
An interesting mechanic that will improve the team play, but also that will also allow you to complete the "Throw different shield items or healing items" challenge.