• Four to six thermal image scanners are being installed at the exit of the Delhi airport to detect fever – a symptom of swine flu – in passengers arriving from the US, the UK, Mexico, Australia, Canada, Chile, Japan and Spain.
• If these scanners improve detection, similar ones will be installed at all busy international airports, such as Mumbai and Hyderabad.

  What are Thermal Scanners?

• These scanners are devices that use thermal imaging to assess the skin temperatures of people as they pass through a checkpoint, and transform that data into a colored image on a screen.

 How does it work?

• A thermal scanner detects the temperature by measuring the amount of infrared radiation emitted by a body. The higher a body’s temperature, the more infrared radiation it emits, making detection possible.
• When someone with fever – higher than the normal 37 degrees Celsius – passes through a Checkpoint, the high-temperature areas get highlighted a particular color, often red or green.

 How reliable are the results?

• Though the scanners are sensitive, ambient temperature of the airport, which is often high in India, can affect its accuracy, as can operator training or stress or agitation levels of a passenger.
• That’s why scanners are used for initial screening. Those monitoring the screen stop the person for further check-ups to determine whether the rise in temperature is because of fever, or whether the person is agitated.

 Does who recommend it?

• No, According to WHO, scanners cannot be solely relied upon to detect swine flu as many infected people develop fever some days after getting infected.

 Are Countries using it?

• Countries like China, Thailand, Indonesia, Malaysia, Japan, South Korea and Singapore are using Thermal Scanners.