A screening system, comprising: a controller; a device housing; a first temperature sensor operably connected to the controller and supported by the housing, the first temperature sensor having a first field of view; a second temperature sensor separate from the first temperature sensor and operably connected to the controller, the second temperature sensor having a second field of view; and a heat source, supported by the housing, operably connected to the controller, and disposed at least partly within the first field of view of the first temperature sensor and within the second field of view of the second temperature sensor, wherein: the first temperature sensor is configured to simultaneously determine a temperature of a measurement site on a skin surface of a subject, and a first temperature of the heat source, without contacting the subject and the heat source, the second temperature sensor is configured to determine a second temperature of the heat source, and the controller is configured to: determine that the second temperature of the heat source determined by the second temperature sensor is substantially equal to a maximum threshold temperature, and determine whether the temperature of the measurement site determined by the first temperature sensor is above the maximum threshold temperature based on the first temperature of the heat source determined by the first temperature sensor and the second temperature of the heat source determined by the second temperature sensor. a controller; a device housing; a first temperature sensor operably connected to the controller and supported by the housing, the first temperature sensor having a first field of view; a second temperature sensor separate from the first temperature sensor and operably connected to the controller, the second temperature sensor having a second field of view; and a heat source, supported by the housing, operably connected to the controller, and disposed at least partly within the first field of view of the first temperature sensor and within the second field of view of the second temperature sensor, wherein: the first temperature sensor is configured to simultaneously determine a temperature of a measurement site on a skin surface of a subject, and a first temperature of the heat source, without contacting the subject and the heat source, the second temperature sensor is configured to determine a second temperature of the heat source, and the controller is configured to: determine that the second temperature of the heat source determined by the second temperature sensor is substantially equal to a maximum threshold temperature, and determine whether the temperature of the measurement site determined by the first temperature sensor is above the maximum threshold temperature based on the first temperature of the heat source determined by the first temperature sensor and the second temperature of the heat source determined by the second temperature sensor. the first temperature sensor is configured to simultaneously determine a temperature of a measurement site on a skin surface of a subject, and a first temperature of the heat source, without contacting the subject and the heat source, the second temperature sensor is configured to determine a second temperature of the heat source, and the controller is configured to: determine that the second temperature of the heat source determined by the second temperature sensor is substantially equal to a maximum threshold temperature, and determine whether the temperature of the measurement site determined by the first temperature sensor is above the maximum threshold temperature based on the first temperature of the heat source determined by the first temperature sensor and the second temperature of the heat source determined by the second temperature sensor. determine that the second temperature of the heat source determined by the second temperature sensor is substantially equal to a maximum threshold temperature, and determine whether the temperature of the measurement site determined by the first temperature sensor is above the maximum threshold temperature based on the first temperature of the heat source determined by the first temperature sensor and the second temperature of the heat source determined by the second temperature sensor.