Short Rest: A character must consume 1 ration to be able to hold a Short Rest in the wilderness. This ration can come from an Equipment Pack. Resting in extreme environments requires proper shelter, or you cannot roll hit dice to recover health.
Long Rest: A character must consume 1 ration and sleep somewhere comfortable (such as a tavern or campsite) to benefit (recover spell slots, Hit Die, HP) from a Long Rest. Camping supplies and rations can be found in an Equipment Pack.