Difficulty: Summiteer (Level 3)

The city of Canoas in Brazil was one of the hardest hit by floods in the region. Hundreds of volunteers there have set up a makeshift dog shelter in an abandoned, roofless warehouse. They treat and feed sick, hungry or injured dogs, hoping to reunite them with their owners.

There is no official tally for the number of animals that have died or were made homeless by the floods, but local media estimated the number to be in the thousands.

The makeshift shelter is about the size of a soccer field. It has taken in hundreds of canines from overwhelmed areas. Every hour, between 20 and 30 dogs arrive. Many were injured after having been run over or nearly drowned. The shelter sends some to veterinary hospitals, but others in need of medical attention are too frail to be moved.

Heartwarming photos online have spurred Brazilians to send donations to the region.