S= 343m/s
F=256Hz
WL= 343ms/256-1
WL=V/F
= 1.339844m
So we want to know how can we detect infrared rays without an instrument. Infrared rays or heat, are a part of electromagnetic spectrum. We have specialized nerve cells in our skin called thermoreceptors that can detect differences in temperature that are produced by infrared part of EM spectrum.
