This research also aimed to find out at what level sleep deprivation was equivalent to the minimum amount of alcohol concentration considered dangerous. Furthermore, the participants were women and men aged 30 to 49 who belonged to a road transport company or the army. Participants were measured in seven different tests, previously chosen based on their sensitivity to the effects of fatigue. The drip presented was about fatigue at two different levels, caused by alcohol and lack of sleep. While the DV measured was the performance in the seven fatigue-sensitive tests. The researcher operationalized the DV by measuring the scores obtained in the different tasks. Additionally, participants had to rate how tired and alert they were. The results showed that after 17 to 19 hours of sleep deprivation, performance scores decreased to a value equal to or lower than that of a person with the minimum level of alcohol considered dangerous. Furthermore, the researchers found that sleep deprivation also decreased participants' alertness, which is an important skill to possess when