PURPOSE: A temperature-sensitive polymeric material for use in a temprature detector/controller of a heating element such as an electric heating blanket, consisting mainly of a copolyamide obtained from a specified lactam or ω- amino-carboxylic acid with a specified diamine/dicarboxylic acid mixture.

CONSTITUTION: 50W95wt% lactam of formula I a or ω-amino-carboxylic acid of formula I b (wherein R1 is H or a 1W30C linear or branched alkyl and m is 5W13) is copolymerized with 50W5wt% equimolar mixture or salt containing a diamine of formula II and a dicarboxylic acid of formula III (wherein R2 and R3 are each H, a 1W12C linear or branched alkyl and m is 1W10). The titled temperature-sensitive polymeric material is obtained by using the produced copolymer together with additives (plasticizers, weathering stabilizer, etc.) in amounts within a limit not detrimental to its electrical properties. In the figure showing a heat-sensitive, temperature-controlling wire, 3 is a polymeric temperature-sensitive element and 5 is a heater wire.