How can excessive heat in a computer room affect users?

Excessive heat in a computer room can significantly impact users by increasing the risk of dehydration. When temperatures rise, the body tends to sweat more to regulate its internal temperature. This can lead to fluid loss, and if users do not replenish their fluids, they may become dehydrated. Dehydration can result in various symptoms such as headaches, fatigue, and decreased cognitive function, all of which can hinder performance and comfort while using computers.

In contrast, the other options do not hold true in the context of excessive heat. For instance, rather than improving concentration, high temperatures can distract users and make it difficult to focus. Additionally, excessive heat does not enhance performance; on the contrary, it can negatively affect productivity and effectiveness. Lastly, heat does not reduce eye strain; rather, it can lead to discomfort that may increase eye fatigue as users try to adjust their work environment to cope with the discomfort.