As you know, maintaining the proper food temperature is critical to food safety.
The FDA Food Code states that the temperature Danger Zone is
41°F-140F° / 5°C - 60°C.
Therefore it is critical when holding hot food, that you use chafers and food-warming boxes that keep foods above 140°F/60°C.
[Source: FDA Food Code (www.fda.gov) and National Restaurant Association’s ServSafe (www.nraef.org)]