“Light therapy…can help reduce shift lag (Dawson, et al., 1994). In light therapy, workers are exposed to bright light during the time the body starts lowering its temperature, which is normally around 4 or 5 a.m. This bright light causes the body to increase melatonin levels, which increases alertness” (Oexman, Knotts, & Koch, 2002, p. 154).
Oexman, R.D., Knotts, T.L., & Koch, J. (2002, December). Working while the world sleeps: A consideration of sleep and shift work design. Employee Responsibilities and Rights Journal, 14(4), 145 - 157.