Real time and location-specific assessment of all HHE occuring at a hematology ward (University Hospital Basel, Switzerland) was performed from 01.03.12 to 28.02.13 using the Ingo-man Weco; Ophardt Hygienetechnik, Issum; Germany. The total number of HHE as well as all HHEs performed in the patient rooms and at the benches were correlated with the number of invasive procedures performed in the patients rooms (change of wound dressing; application of i.v. medications, blood withdrawel/puncture of vessels, lumbar/bone marrow puncture) and at the benches (preparing i.v. formulations) on a daily basis. Data on invasive procedures derived from the electronic patient data sheet.