Infrared radiations falling on material are easily
absorbed by water molecules present in them.
As a result of it, the thermal motion of the water
molecules present in material increases. Due to
it, the material gets heated. That is why infrared
radiations are often referred to as heat waves.
(i) The radiations, next to infrared radiations,
having shorter wavelength will be visible light.
(ii) The radiations next to infrared radiations,
having longer wavelength will be microwaves.