Usually a hot nosed dog, cannot (or will not) work a cold trail. They instead will have a tendency to lay back and let a cold nose dog work the trail until it warms the trail up (gets closer to the game). Then the hot nose will work ahead of the slower dog, and tree the game, thereby getting the credit for the tree.
In the field under actual hunting conditions these type of dogs (hot nose dogs) are useless, unless you accidentally dump them out right on top of a hot track, or you have a cold nose dog, figuring out the track.