Open water baths as a source of contamination
The danger with the use of water baths, especially in hospitals and blood banks, lies in nosocomial infections, also known as hospital germs. Such an infection affects those patients who have been admitted for a reason other than this infection. The patients become infected during their hospital stay, and symptoms can occur both during the stay and afterwards. Likewise, these infections can also affect staff members. 
Known sources of nosocomial infections can be contaminated blood plasma bags that have been contaminated by direct contact with water, moist surfaces, or via indirect transmission through improper use or inadequate cleaning of medical equipment.
Nosocomial bacteria are particularly dangerous for hospital patients because they already have a weakened immune system due to their original illness and are exposed to them through various medical procedures and invasive treatments. Illnesses caused by hospital germs can be ear and eye infections or severe pneumonias (especially in elderly patients). This requires a prolongation of their hospital stay, increased costs for diagnostics, laboratory and treatment.
Not only are elderly patients are at risk, but also those with weakened immune systems, intensive care patients and transplant patients. 
Simple measures can be taken for prevention infection, such as proper hand cleaning and disinfecting practices with the use of antiseptic soap, avoiding wearing jewelry and glove wearing can promote prevention. In addition, of course, disinfection of medical equipment and the areas to be treated. Last but not least, the renunciation of open water baths as a major source of hospital germs and the switch to dry temperature control devices.  
 O’Shaughnessy, D.F, et. al. (2004): Guidelines for the use of fresh-frozen plasma, cryoprecipitate and cryosupernatant, The British Society for Heamatology, 126, 11-28, p. 18
 Ducel, G., Fabry, J., Nicolle, L. (2002): Prevention of hospital-acquired infections – A practical guideline, 2nd edition, World Health Organization (WHO), p. 1
 National Institute for Health and Care Excellence (2011): Healthcare-associated infections: prevention and control, p.8
 U.S. Department of Health and Human Service; Centers for Disease Control and Prevention (CDC) (2003): Guidelines for Environmental Infection Control in Health-Care facilities - Recommondations of CDC and Healthcare Infection Control Practices Advisory Committee (HICPAC)