The word “ice” is so popular that a lot of regular carbon steel scissors and shears proclaim to be Ice Tempered, which does not make any sense technically.
Some people even think “ICE” is a brand name.
The important thing to remember is that ice tempering is only beneficial on stainless steel.
In a simplified form, stainless steel is regular steel with chromium added to make the steel more rust resistant, thus “stainless” steel.
The disadvantage of the high content of chromium in stainless steel is that the cutting edges dull quicker.
To overcome this, the steel is subjected to very low temperatures (frozen or “ice tempered”), to optimize the steel structure for hardness.
This is how it works:
To make steel hard, it has to be heat treated. With stainless steel, that means heating the steel above 2000 degrees Fahrenheit.
At that temperature the structure of the material is at its optimum. To preserve this structure, the steel is cooled rapidly (quenched) and tempered at about 450 degrees Fahrenheit.
Now you have a pretty good hardness and flexibility on your tool except that the chromium in the steel will not permit a long lasting cutting edge. To make the cutting edge last longer, the steel is subjected to about 120 degrees below zero; in other words, “Ice Tempered”. The tool is not much harder, but the steel structure is at its optimum. It is virtually impossible to prove or disprove if ice tempering was done, without a steel analysis.