Contains Non-binding FDA Recommendations

Dotty is preparing these responses in accordance with the recently published guidelines from the FDA “Enforcement Policy for Telethermographic Systems During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency Guidance for Industry and Food and Drug Administration Staff April 2020”

Dotty is following the recommendations of the FDA where possible to inform users of the limitations of this non-medical screening device and recommendations for secondary screening if required by the local governing guidelines.


Primary Disclaimers:

  1. This is not a medical device, and is not approved by any medical bodies including the FDA. These FDA guidelines are for the safe use of non-medical screening systems.
  2. Measurement should not be primarily relied upon to diagnose any disease. This is an abstract temperature measurement for the sole purpose of screening for a potentially Elevated Skin Temperature only.
  3. Elevated Skin Temperature in the context of use should be confirmed with secondary evaluation methods (e.g., an NCIT or clinical grade contact thermometer), if a further screening or diagnosis is required by a medical professional.

Performance Specifications (addressing section D performance and labeling)

  1. a) The laboratory temperature accuracy of a screening telethermographic system, including

the measurement uncertainty, is less than or equal to ±0.5°C (±0.9°F) over the temperature range of at least 34-39°C (93.2-102.2°F);

Dotty’s Elevated Skin Temperature app derives an estimated body temperature of a person based on the medical average for body temperatures of 97.5F. There is no known standards for evaluating absolute internal body temperature from average skin temperatures with any reliability when glasses, masks etc are worn over the face. As such Dotty makes no claim of the absolute accuracy of the app product. Dotty does however define statistical thresholds for normal skin temperatures between 95F and 99F, elevated outliers between 100.4F and 103F and 103F+. In all cases Dotty recommends secondary medical screening if this data is to be used in ways not intended by the app as a front of house, self-screening device.

Dotty has carried out rigorous internal testing to the best of our abilities to ensure results are accurate to within 0.9F of the thresholds used for the 3 result ranges offered, 95-100.4F, 100.4F to 103F, 103F +.

  1. b) The system includes an accurate blackbody temperature reference source;

Dotty does not measure absolute temperatures, the basic premise for a black body source requirement. Dotty substitutes the need for a black body with setup guidelines that require a wall or ceiling within 15 feet of the static camera system. Dotty’s app tracks this background in a multitude of ways at 9FPS and compensates for any drift in the camera system in real time. In the event the background is unacceptable for tracking temperature, the following drift monitoring is triggered.

  1. c) Both stability and drift are less than 0.2°C (0.36°F) within a timeframe specified by the manufacturer;

Dotty tracks the drift corridor between the background relative to the Skin Temperature (assumed to be stable during measurement), and detect if and when a 0.36F divergence occurs, triggering a full system calibration and health check. In the event the health of the system is non acceptable, an app restart will occur. In addition to this Dotty’s system forces regular re-calibrations while the system is in standby and checks that drift is trackable, if not the app restarts.

  1. d) The device risk assessment addresses all potential safety issues, including:
  2. i) Electrical safety;
  3. ii) Electromagnetic compatibility;

iii) Mechanical safety;

  1. iv) Excessive temperatures and other hazards;
  2. v) Accuracy of controls, instruments, and information display;
  3. vi) Considerations for software associated with Programmable Electrical Medical

Systems including network connections;11 and


Dotty does not provide the hardware accessory to the solution powered by iPad or iPhones. Dotty does however have a strict hardware support criteria such that the hardware conforms to the most strict compliance standards. Dotty only recommends Apple’s MFi certified hardware. As such this hardware passes all of the above standards as can be checked directly with the hardware on purchase (separate to Dotty’s app).

Dotty does not see any foreseeable risk in the iPad or app software that constitutes any further Test and Measurement requirements.