The term 'consequences of an all-nighter' can refer to the physical and mental effects that result from staying up all night. The crossword solution REDEYES is a reference to one of the most common physical effects of an all-nighter, which is having red eyes due to lack of sleep. Other physical effects can include headaches, fatigue, and difficulty concentrating. Mentally, an all-nighter can lead to impaired decision-making, irritability, and difficulty focusing.