A security system and method for collecting and analyzing thermal data to save power and identify persons. The security system includes a processor with connected processor and one or more additional devices such as an alarm, lighting device or visual light camera. When the security system is in a low power sleep mode, the thermal sensor detects and collects thermal data from a thermal object body and the processor determines if the collected thermal data matches predefined parameters for a thermal body and then activates any one of one or more of the connected additional devices based on the match. The system is then operational to collect visual data and process the collected thermal and visual data to match against stored profiles. The thermal data may be collected at low or no light conditions to determine the need to power up the system to collect visual data.