We know it's only a hint of the challenge that homelessness represents, but your students will make a meaningful connection to the cause.
Every school campus is different, but we suggest mapping out a clockwise route around your schoolyard. If that doesn't work, consider:
Aim to be outside long enough to 'feel the cold' wherever you are - that's the connection to the cause. But just standing around outside doesn't quite suffice: students need to do something and have a physical purpose. A walk works well because it's simple and students of all fitness levels can participate. (And it's pretty easy to organize!)
Get your planning team to walk the route well before event day so that you know how long it takes to do one 'lap'. That will allow you to estimate how many laps your students need to complete to get in about an hour, and plan accordingly.