The city of Detmold no longer heats its outdoor pools. She wants to save gas and be a role model. What are the swimmers saying in the outdoor pool? And what does the measure actually achieve?

The stone floor on the way from the changing room back to the pool in the Hiddesen outdoor pool in Detmold is cool. Have a quick shower. Get your body used to the water temperature of 24 degrees – two degrees less than in June.

The city in North Rhine-Westphalia is setting an example, wants to save gas and no longer heats its outdoor pools. At 23 degrees, the air is one degree lower. A light breeze is blowing this morning. Now and then a cloud moves in front of the sun – to speak of Putin’s dark shadow here would probably be an exaggeration.

The water in the 50-meter pool on the edge of the Teutoburg Forest glows a seductive blue. About 15 swimmers cavort on the eight lanes. The usual suspects one morning a week. Here two women and a man on lanes two to four. The group knows each other and chats while swimming. There on lane 1, a woman takes a short break in the corner, calls over and asks for an acquaintance she hasn’t seen in a while. There are only a few students in the pool, although the holidays in North Rhine-Westphalia have long since begun.

Swimmer: “I don’t notice anything”

Everything as always in Detmold? What is it like when a city government orders savings so that the gas storage tanks can be filled against the background of the Russian war of aggression in Ukraine? The middle-aged swimmer on lane 5 is surprised. She hadn’t heard anything about the city’s action in all four outdoor pools. “What, two degrees colder? I don’t notice anything,” said the woman and continued swimming.

The woman on lane 3, who claims to be 81 years old and looks much younger with black hair, is actually very relaxed, but wants to briefly express her indignation. “Older people need a little more temperature. We’re already noticing that,” she says plaintively. “Now we have to move on, we’re not done yet.” Her swimming friend on lane 2 asks why it has to be so radical. “Why turn off the heating completely, wouldn’t it also help if at least some heating was still on?” – and quickly push off for the next lane.

Children and young people would certainly not come now when the water is colder, the duo had previously thrown in on lanes 2 and 3. Isabel Bark, deputy chairman of the Hiddesen outdoor pool initiative, is relaxed. The weather has been good so far, and the association that oversees the operation of the pool has not noticed a drop in visitor numbers after the city announced.

Security of gas supply

Miriam Mikus, Detmold’s first deputy, explains: “In the management of DetCon, which also includes the management of the public utility company, we considered that it would now be good to take a first step towards security of supply for gas next winter.” The trigger was the declaration of the alarm level by the federal government. “That’s why the decision was not made at the beginning of the outdoor pool season, but only at the end of June,” says Mikus of the dpa. “The problem: Because of the water shortage in the region, we also want to start a campaign to get people to save water. For example, by using less water in private pools.”

So we thought about it and weighed it up. “The decision was then made in favor of security of supply for gas, since water can also be saved in other ways and it can currently be assumed that we will have a warm summer. And then the water temperatures remain pleasant for swimming.» Initial reactions from citizens were mixed. There was praise, but also immediate criticism. How much the city would save in euros was not calculated. But the amount of gas. “Per year that would be the consumption of 100 households of four people each. For the current year, we will save gas for around 65 four-person households,” says Mikus.

Freeze against Putin? In the outdoor pool in Detmold it only gets a little uncomfortable above the water surface. The wind is fresh. After around 45 to 50 minutes, it gets cold in the water too, despite movement.

No problem in the warm summer

This is confirmed by Andreas Bieder from the German Sport University in Cologne. The swimming expert sees rather pleasant water temperatures in a Central European summer. “An hour of swimming at 22 degrees is not a problem,” says Bieder. When the outside temperatures are cooler, visitors to the outdoor pools simply vote with their feet and no longer go to the outdoor pool.

“I see more of a problem when the water is too warm. There is a risk of hyperthermia. The body overheats because it cannot dissipate the heat generated by muscular strength while swimming,” says the expert. But this problem does not play a role in popular sport. More like open water swimmers in the professional sector, where deaths recently made the headlines.

A water temperature of between 26 and 27 degrees is ideal for competitions – the feel-good temperature for athletes. According to the rules of the German Swimming Association (DSV), the temperature must always be included in the competition record. However, there is no rule for the number of degrees. Only for young people the water must not drop below the limit of 18 degrees Celsius.

And fat helps against cold. “When swimming in cold water, the body core temperature drops, but only significantly after several hours and depending on the body fat percentage, which is why experienced channel swimmers actually put on a layer of fat,” explains Bieder. However, these swimmers are experienced and used to cold water. However, visitors to the outdoor pool in Detmold are still a long way from these conditions during the summer months.