Do I need to use hot water to wash my hands?
Amy Simonne, Ph.D., Associate Professor, Food Safety and Quality and Suzanna P. Bonard, MS Student.
Experts agree that handwashing is one of the best ways to prevent communicable diseases. However, when it comes to understanding the role that water temperature plays in the removal of microbes from hands, limited literature is available.
According to Laestadius and Dimberg (2005), water temperatures can be classified as cold (<65°F or <13.3°C), cool to tepid (65 - 90°F or 13.3 - 32.2°C), warm (90 - 98°F or 32.2 - 36.7°C) and hot (98 - 105°F or 36.7 - 40.6°C). The normal body temperature of a healthy human is 98.6°F or 37°C. Many food regulatory agencies recommend warm water for handwashing. However, many studies have shown that water temperature is not as important as the actual mechanical action of handwashing. In fact, hot or very warm water may be a major cause of skin irritation for people who wash their hands multiple times per hour, especially healthcare workers going from patient to patient. Therefore, recommendations for hand hygiene in health care settings are different from recommendations for the general public or other sectors, such as food service.
What is the take-home message? Wash your hands in water at a temperature that feels comfortable to you. It is not necessary to provide a hot water tap. This will also help facilities save money.
- Laestadius JG, Dimberg L. Hot water for handwashing-Where is the proof? [Letter]. Journal of Occupational & Environmental Medicine. 2005; 47(4):434-435.
- Michaels B, Gangar V, Schultz A, et al. Water temperature as a factor in handwashing efficacy. Food Service Technology. 2002; 2:139-149.
- Michaels B, Gangar V, Schultz A, et al. Handwashing water temperature effects on the reduction of resident and transient (Serratia Marcesens) flora when using bland soap. Dairy, Food and Environmental Sanitation. 2001; 121:12-21.
- Food and Drug Administration. FDA Model Food Code 2005. Available at:
- Centers for Disease Control and Prevention. 2002. Guideline for hand
hygiene in Healthcare Settings - 2002.
- Simonne A. 2008. Hand Hygiene and Hand Sanitizers.
Prepared by Amy H. Simonne, Ph.D. Associate Professor and Suzanna P. Bonard, MS Student. For more information contact: Dr. Simonne at firstname.lastname@example.org