Why do you have strange dreams when you have a fever?

Usually a person’s body temperature drops as evening approaches. It makes it easier to fall asleep and stay asleep. Body temperature is at its lowest just before nightfall, around 2-3 o’clock.

In fever, the increased body temperature disturbs sleep. Sleep becomes lighter and more intermittent. The content may become strange for many people, the mood more intense than usual and even scary.

A fever is a state of stress for the whole body. Fever easily causes a load on the body and, for example, a feeling of anxiety both when awake and in sleep. The experiences during waking hours are also reflected in the contents of dreams. During a fever, you may also wake up often, which means you remember your dreams more.

It is important to take care of general well-being during a fever. The clothing should be light enough and the sleeping environment cool. It is important to take care of drinking enough and getting energy. Namely, the changes in the metabolism that regulates the body’s functioning also affect sleep.

Tiina Paunio

professor of psychiatry and chief physician

University of Helsinki, THL and HUS

How do fish talk to each other?

Sylvia Valtonen, 8

Although fish do not speak in the same way as humans, they have many different ways of communicating with each other. It also happens with sound.

Many species of fish produce sounds such as clicks and crunches, for example by rubbing bones and muscles and using the swim bladder as a sounding board.

The importance of producing and hearing sounds can often be great, for example, when a predator approaches, itches, i.e. reproduces, or when a school of fish moves. For example, mates have been found to communicate with a drumming sound during kudu. The researchers named this mate song.

Fish don’t have external ears for hearing like humans, but they sense sound vibrations with their inner ear and rib sense. Those vibrations travel through the water to the inner ear directly through the soft tissues of the fish’s body. With the help of the lateral line sense, the fish, on the other hand, can feel the movements of the water and the changes in the vibrations.

Some fish species sense sounds clearly better than others. Species without a swim bladder, such as flounder, have generally proven to be poor listeners. Those species whose body has a connection from the inner ear to the swim bladder are, on the other hand, good listeners. For example, the common aquarium species goldfish is good to hear.

In addition to sounds, fish communicate with e.g. body movements, color changes or so-called pheromones, which are chemical compounds. Some fish, such as the electric eel, even communicate with electric shocks.

Teppo Vehanen

docent of fish biology

Natural Resources Center

Why do the eyes get teary when yawning?

Mea Mattila, 12

Tears can be divided into three groups: tears that constantly maintain eye moisture, tears related to emotional experiences and reflex tears. Tears produced during yawning are reflex tears. The eyes get wet automatically during yawning, and we can’t really control that.

The tears that come with yawning are produced by the so-called parasympathetic nervous system, which is part of the involuntary nervous system. The parasympathetic nervous system prepares us holistically for rest. It may be that yawning with tears relaxes the body more than yawning without tears.

The simultaneity of yawning and tearing eyes is also supported by the fact that the brain nerves that regulate the muscles needed for yawning and the flow of tear fluid command them to work together.

In practice, tears start to come into the eyes when yawning, when the yawning muscles are activated. In this case, the function of the lacrimal glands is activated. The bigger the yawn, the more likely the tears will come to the eyes.

Tiina-Kaisa Kukko-Lukjanov

university lecturer in physiology and specialist researcher

University of Helsinki

Why do you get hooked on browsing and watching series on your mobile phone?

Veera Kankaanpää, 9

Osa of mobile phone applications are designed to make everyday life easier. Such are, for example, electronic library cards and bank IDs. However, the majority of applications are designed specifically to hook.

In their design, researched information about what kind of things fascinate the human brain has been used. If you almost complete a task in the game, you’ll want to try again. Similarly, at the end of the series, some plot pattern is often left unfinished, which makes you want to continue watching. In addition, in the streaming service, the next episode starts without you having to do anything.

If, on the other hand, social media content causes an emotional reaction, be it surprise, admiration or irritation, the brain thirsts for more content. Bright colors, flashes and music and surprises easily tickle the mind.

When there is a lot of different content on offer, it is easy to lose track of time. In the end, you can visit the buffet table like you often do: you end up enjoying more than you intended.

A curious mind has enabled the learning of individuals and the development of the human species, so it has been very useful throughout the ages. However, when a person is hooked, curiosity easily gets over. In this case, the person is often restless and concentration suffers.

Many experts want to protect children from the harm of cell phones in the same way as they want to protect them from gambling. Sometimes it is also good to regulate the viewing of media content, such as series.

Silja Kosola

associate professor of adolescent medicine

Western Uusimaa welfare area

Send the question, the questioner’s full name and age to [email protected]. The column is provided by Touko Kauppinen.