Thermal scanners are used to detect the temperature of a surface and, in the case of a person’s skin, can be used to determine the possibility of someone having a fever. A person’s body temperature is generally around 37C degrees, and variations to this may indicate underlying medical conditions. When a person’s body temperature climbs above 38C degrees, they are medically known as having a fever. This fever will cause the person’s skin to radiate heat at higher than normal levels and when in front of a thermal scanner, can be determined as a possible fever. 

thermal scanner image of a persons face

 Thermal scanners will generally alert the operator to a possible fevered individual through an alert, alarm, or colour change on the screen. It is important to note that the accuracy of thermal scanners is questionable based on individual and environmental factors and therefore should be used as a guide only, see what the professional say here. Individual medical circumstances as well as having recently exercised can cause a person’s skin temperature to rise. Environmentally, heat radiating from nearby surfaces can skew the thermal scanner readings. 

In light of this information, thermal scanners may be useful in detecting people with possible fevers but should in no way be used as a conclusive determination of illness. This is important during the COVID-19 pandemic where people exhibiting a possible fever are being denied entry into places on that basis to prevent any possible community transmission-based infections.