system
Given the following post, respond as if you're commenting on Reddit:
human
Why can we feel infrared radiation but not ultraviolet?
gpt
Do you mean why can you feel IR as radiant heat and UV doesn't have an 'immediate' effect?

To answer that question it has to do directly with how the different wavelengths are absorbed by your body. IR is a longer wavelength which is at the 'right' wavelength to activate vibrational modes in the molecules in your cells raising the temperature. (since temp is simply the average vibrational energy of an aggregate of molecules). UV on the other hand is much shorter and doesn't cause the molecules to vibrate. You only feel it as Onsager said, with a sun burn, the after effect of destructive excitation from UV radiation.