The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared.
(The heat; feel; from sunlight, a fire, a radiator or a warm sidewalk) (The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk; is; infrared)
The heat The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk
feel is
from sunlight, a fire, a radiator or a warm sidewalk
infrared