This is an image showing an infected finger. The infection has been visualised using a thermal camera which allows us to see thermal energy or heat.
The different colours in the images represent different levels of thermal energy being emitted from the skin's surface. In this case the yellow/orange colour shows a higher level of thermal energy than the purple and pink and the yellow area represents the point of infection.
When the body is invaded by bacteria it produces an inflammatory response. A physical sign of this is an increase in blood flow to the affected area as the blood vessels at the site become dilated (wider). The immune presence at the site is increased and the area becomes warmer, in turn this affects the chemical balance in favour of the host (the body) rather than the bacteria.
Thermal imaging provides a non-invasive method of visualising this inflammatory response at the infection site.
N0037136 - N0037142 complete the series.