At last year’s Credit Union Cherry Blossom races, thousands of runners crossed the finish line in either the event’s 10 mile or 5K events on a chilly April day. Upon finishing, runners were offered a heat sheet — a mylar blanket that provides a small source of warmth. So when runners are ready to toss the blankets and head home, then what? The race’s sustainability team had a plan to make sure there was an eco-friendly option.

Instead of letting the nearly 20,000 blankets end up on the trash, and eventually a landfill or incinerator, there were specific collection points on race day where runners could ditch their heat sheets.