Cole met a medic in the Historic District who requested that he climb to the top of a rooftop and knock down all of the medical supply crates the Feds dropped. Cole managed to do so while fending off several of the First Sons.
This task is fairly simple. There are a total of seven crates you must knock down. Simply locate each crate by the special red circles on your GPS map. Of course, you'll have a bunch of First Sons troops to deal with. Use Cole's blasting power to help you in this mission. Completing this mission rewards you with 100 Experience points and slightly reduces enemy activity in the Historic District.