First find the total distance Carson walks along the warehouse's long sides: 600 feet/side * 2 sides = <<600*2=1200>>1200 feet
Then find the total distance Carson walks along the warehouse's short sides: 400 feet/side * 2 sides = <<400*2=800>>800 feet
Add those two amounts to find the total distance walk in one circle: 1200 feet + 800 feet = <<1200+800=2000>>2000 feet
Then find the number of circles Carson actually walks: 10 circles - 2 circles = <<10-2=8>>8 circles
Then multiply the distance of one circle by the number of circles Carson makes: 2000 feet/circle * 8 circles = <<2000*8=16000>>16000 feet
#### 16000