The medical education at The Sahlgrenska Academy in Gothenburg offers in its third semester a student lab called "Vattenbalans" [=Water balance]. The purpose of this lab is to study fluid loss by the kidneys. In total more than 120 students participate, although the urine flow rate is only measured on approximately 50 students each semester. The rest of the students function as secretaries. The lab protocol can be found in "Komplett-laborationskompendium-T2-T3-uppdaterat-150318" pp. 123-134.