Fever Cameras FDA guidelines Thermal Imaging Blackbody Calibration Devices Poor Setup
As Six Flags scrambled to reopen parks amid plummeting revenues caused by the pandemic, it deployed Dahua fever cameras outdoors that violate FDA guidelines, creating a false sense of security and increasing risk to guests.
Despite that, Six Flags marketed Dahua devices as “new cutting edge thermal imaging” while showing false readings of up to 108° in its own marketing.
This one-minute video summarizes the problems:
In this post, IPVM examines this issue in-depth.
Due to COVID, Six Flags’ revenue dropped 96% in Q2 2020 and its stock price has fallen by about 50%. Currently, only a fraction of Six Flags parks worldwide are open.
To reassure visitors and investors, in May, Six Flags began promoting new safety measures such as mandatory mask wearing and what they claimed to be “state of the art thermal imaging for temperature checks”.
108°F Temperature Readings In Marketing
However, Six Flag’s own marketing video showed the problems with its outdoor temperature screening. In the segment where it touts this ‘cutting-edge thermal imaging’, the subject in the center of the screen’s temperature is measured at 102, 105, 107, even 108.7°F, as the excerpt below shows:
Given IPVM’s testing of this Dahua system and dozens of other ‘fever’ systems, this inaccuracy, while concerning, does not surprise us. And while many organizations have made poor decisions on screening, it does surprise us that a publicly-traded company who historically has had ten of millions of annual guests would be so careless to display an obvious faulty set up in its own marketing.
New Thermal Imaging Has Numerous Problems
IPVM reviewed walkthrough videos for each currently open Six Flags park in the US from YouTubers and found numerous FDA fever screening guidance violations:
- Outdoor screening deployments fundamentally undermine guidance, as they cannot stop ‘draft (movement of air)’ and they cannot ensure the ‘temperature should be 68-76 °F (20-24 °C) and relative humidity 10-50 percent’. Temperature and humidity can vary greatly over the year and even during the course of a day. For example, this week Six Flag’s NJ park will have temperatures ranging from 38°F to 61°F and multiple days with humidity of 80%+.
- The FDA advises “at least 15 minutes” of wait time for people in a “measurement room” until they are screened by a thermal camera. However, visitors enter Six Flags’ fever screening areas immediately from outdoor queuing areas with no little to no adjustment period. This means outside weather conditions (hot sun, cold rain, etc) will impact skin temperature readings.
- Blackbody calibration devices on Six Flags’ fever screening systems are placed close to the thermal camera, violating FDA guidance that the blackbody is placed close to people being screened. This skews system accuracy as blackbodies are meant to be compared directly to human body temps and major manufacturers – including Dahua – say they function properly only if placed next to humans, which IPVM testing confirms.
- FDA guidance advises screening be carried out in rooms with “no draft (movement of air)” but Six Flags’ screening ‘tents’ typically have large air conditioning systems and/or fans blowing onto visitors. International guidelines also advise these systems avoid “drafts from sources such as air conditioning ducts” so that people’s faces are not artificially cooled.
- The FDA advises “any face obstructions” be removed, including hair and masks, however, Six Flags allow masks and hair obstructions to remain.
- The FDA states “measure only one person” at a time but IPVM found multiple instances of Six Flags parks doing simultaneous screening.
In many cases, Six Flags’ poor setups violated Dahua’s own install instructions as well, as we show below.
Screened Immediately After Queuing Outside