Heat affects your ability to perform. This is the conclusion of a new study, performed at the American university Harvard T. H. Chan School of Public Health. When you sleep in a warm bedroom, your brain can be, temporarily, affected in the morning.
The study was performed by testing the cognitive abilities of 44 students in the morning hours. Every morning, the students had to complete a series of tests.
The scientists compared the results of students, who had air condition in their room, with students who had to sleep in the heat. The results showed that the chilled students performed better the following morning.
Especially reactions and memory were affected
The students without access to air conditioning were on average both slower and had more incorrect answers in their tests. After having slept in a hot room, reactions and memory were especially affected. The difference between the two groups of students was most noticeable in the difficult sections of the tests.
If the brain is to solve simple tasks, heat doesn’t make a significant difference - however, if the tasks are more complex, heat will affect the brain’s ability to perform. It gets progressively worse if one adds dehydration to the mix.
Dehydration and heat can be connected; if you sleep in a hot room, the risk of dehydration is greater. The Danish scientist Lars Nybo, whom have studied temperature regulation and ability to perform, explains to dr.dk (a Danish news outlet), why fluid balance is important: “If you sleep in a place without air conditioning or ventilation, it will affect your fluid balance. If one is just a little dehydrated when waking up, one will perform worse on cognitive tests.”
What happens to the brain?
Besides the risk of dehydration, it is difficult to say why the brain performs worse in the heat. Exactly what happens to the brain, when it is exposed to heat, is still being debated between scientists. However, some scientists believe that the neurons operate at a decreased rate and will be slower in communicating with each other when it gets hot.
21°Cnegatively affect our cognitive abilities
An earlier American study showed back in May 2018 that high temperatures in classrooms affect the students’ learning and ability to perform. The study showed that 21°C is the key figure – above 21, the heat begins to affect the brain and the students will learn less and perform worse during lectures.
The study showed that the years with higher temperatures during exam periods, had students with lower grades, as opposed to years with colder weather during exam periods.
Besides heat, air quality also plays an important role on the brain’s ability to perform. If the room had good ventilation, the brain functions better, than if the room is lacking fresh air – regardless of temperature.