Not all research samples "live" in a lab. Sometimes they need to be transported from where they are being stored to where you will be doing your data collection.
Sometimes older European buildings do not have elevators.
Sometimes labs are located on the 3rd floor of older European buildings with no elevators.
Sometimes you and your host/colleague have to carry 40+ boxes of archaeological remains that still need to be cleaned and have various amounts of heavy dirt in them up 3 flights of stairs to the lab in an older European building with no elevator.
And sometimes you just have to hope that your host isn't deeply regretting their decision to allow you to do research at their facilities.