A total air temperature probe having a self-regulating heating system comprising: a TAT probe housing including at least one heating cavity, the at least one heating cavity including a heating cavity proximate to a tip of the TAT probe; a heating element received within the at least one heating cavity, the heating element composed from a flexible material with a positive temperature coefficient, a composition of the heating element being varied to provide non-linear resistance with temperature with lower electrical resistances at temperatures below the freezing point of water and higher electrical resistances above the freezing point of water, the heating element being self-regulating and self-limiting at locations across an active surface of the heating element; a power source (82, 430) coupled to the heating element, wherein the PTC material of the heating element causes less power draw by the heating element from the power source (82, 430) at higher temperatures above the freezing point of water than a power draw by the heating element from the power source (82, 430) at lower temperatures below the freezing point of water in maintaining a desired temperature of the TAT probe; a heat shield defining an inlet passage to a sensor element, the heat shield further defining a portion of the at least one heating cavity, the heat shield further positioned to block heat radiated by the heating element to either the sensor element or an air flow measured by the sensor element; and the TAT probe housing further having an airflow passage to direct air flow across the heating element received within the at least one heating cavity. a TAT probe housing including at least one heating cavity, the at least one heating cavity including a heating cavity proximate to a tip of the TAT probe; a heating element received within the at least one heating cavity, the heating element composed from a flexible material with a positive temperature coefficient, a composition of the heating element being varied to provide non-linear resistance with temperature with lower electrical resistances at temperatures below the freezing point of water and higher electrical resistances above the freezing point of water, the heating element being self-regulating and self-limiting at locations across an active surface of the heating element; a power source (82, 430) coupled to the heating element, wherein the PTC material of the heating element causes less power draw by the heating element from the power source (82, 430) at higher temperatures above the freezing point of water than a power draw by the heating element from the power source (82, 430) at lower temperatures below the freezing point of water in maintaining a desired temperature of the TAT probe; a heating element received within the at least one heating cavity, the heating element composed from a flexible material with a positive temperature coefficient, a composition of the heating element being varied to provide non-linear resistance with temperature with lower electrical resistances at temperatures below the freezing point of water and higher electrical resistances above the freezing point of water, the heating element being self-regulating and self-limiting at locations across an active surface of the heating element; a power source (82, 430) coupled to the heating element, wherein the PTC material of the heating element causes less power draw by the heating element from the power source (82, 430) at higher temperatures above the freezing point of water than a power draw by the heating element from the power source (82, 430) at lower temperatures below the freezing point of water in maintaining a desired temperature of the TAT probe; a heat shield defining an inlet passage to a sensor element, the heat shield further defining a portion of the at least one heating cavity, the heat shield further positioned to block heat radiated by the heating element to either the sensor element or an air flow measured by the sensor element; and the TAT probe housing further having an airflow passage to direct air flow across the heating element received within the at least one heating cavity.