Not always noticed during said hump (due to adrenaline) but becomes immediately obvious once you step into a hot shower.
Can be prevented by wearing compression shorts (Spandex) in the place of your standard undergarments (boxers or briefs).
The difference between a hike and a hump is that a hump involves carrying gear. One can hike with a day pack, a water bottle and a camera. One humps when they are carrying items of greater density such as tents, field rations, ammunition for the mortar and a rocket launcher used for destroying enemy tanks.