July 4, 2025, 8:44 am | Read time: 5 minutes
Is the compartment stuffy? It’s not pleasant, but manageable. But what if the air conditioning fails during high outside temperatures and the situation becomes concerning? TRAVELBOOK explains what to do in such cases.
If the air conditioning on a train isn’t working properly or fails completely, it can quickly become unbearable for passengers on hot days. They should immediately speak to the train staff, advises Karl-Peter Naumann from the passenger association Pro Bahn. Many trains are also equipped with intercom systems that allow passengers to contact the train driver and report issues. This is especially useful when cars are coupled separately, as is often the case with many regional and S-Bahn trains.
“It’s important that the train staff act immediately,” says Naumann. Ideally, the problem can be resolved by adjusting the air conditioning settings.
Overview
Air Conditioning on the Train Fails Completely–What Then?
In the event of major defects, the train usually attempts to reach the next station for evacuation. For long-distance trains like Deutsche Bahn’s ICE and IC, often only the car with the defect is cleared, explains Naumann. Passengers are then redistributed to cars where the air conditioning is still functioning.
It’s problematic if the train has to stop en route and the air conditioning fails. “A stop on open tracks is a major disaster,” says Naumann. Evacuation is not easily possible. On double-track routes, there’s a risk of oncoming trains hitting disembarking passengers, according to the expert. Even on single tracks, there are risks—such as the danger of injury from the high gap between the train edge and the ground, as there is no platform.
Train operators must quickly call the police and fire department to assist with evacuating the train, says Naumann. If it’s hot and stuffy, some passengers may start experiencing health issues. If no train staff is available, passengers have a last resort: they can also call emergency services, Naumann advises.
And breaking windows to get some air? “You’re not allowed to, but sometimes there’s no other choice,” Naumann says.
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Breaking a Window? Why a Lawyer Sees It Critically
Attorney Philipp Gehrmann advises against breaking train windows. While there is a so-called emergency right when there is an immediate danger to life and limb—allowing damage to others’ property in certain situations.
A commonly cited example is breaking a window when a locked car is in the blazing sun and a child inside appears to be in distress.
However, this scenario cannot be applied to a situation with a defective air conditioning system on a train, says the expert, who is on the executive committee of the criminal law working group at the German Bar Association. For one, there is staff on the train who can open the doors from the inside. Additionally, there may be emergency door opening mechanisms that passengers can activate in emergencies.
Instead, breaking the window without taking these other actions could be considered property damage—and potentially a dangerous interference with rail traffic, according to Gehrmann. He advises calling the police in an emergency. “That’s a better idea than breaking the window.”
Problems with Defective Air Conditioning on Trains Have Decreased
Fortunately, according to Pro Bahn expert Karl-Peter Naumann, issues with air conditioning in trains have significantly decreased in recent years. “Many newer trains with powerful air conditioning systems are in use.” However, technology can always fail, so problems can never be completely ruled out.
For instance, a train from Nordwestbahn came to a halt on a railway bridge on Tuesday due to a technical defect, and the air conditioning only functioned partially, as a federal police spokesperson reported. It quickly became hot, prompting passengers to call emergency services—police and rescue teams arrived to free the nearly 50 affected individuals. According to police reports, five people were treated for circulatory problems and dehydration.
How Deutsche Bahn Sets Temperatures in Long-Distance Trains
Passengers can always contact train staff if temperatures are high, says a Deutsche Bahn spokesperson. The base temperature in the state-owned company’s long-distance trains is set to 23 degrees Celsius according to specified standards and can be adjusted by two degrees up or down based on passenger needs in individual cars.
In summer, the interior temperature can initially be set to 25 degrees Celsius. According to the train spokesperson, this has advantages: the air conditioning can be used as energy-efficiently as possible, and passengers are less likely to feel cold when coming from the heat outside into the cooled compartment.
If the onboard air conditioning is disrupted, all ICE and IC trains carry “sufficient water supplies” that can be distributed, the spokesperson notes. He also points out that cars with malfunctioning air conditioning in long-distance travel are displayed in the DB Navigator app and on bahn.de, “so passengers can orient themselves early.”
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Refund for Delays?
According to Karl-Peter Naumann from Pro Bahn, passenger rights state that if you have to move within the train due to an air conditioning defect, it is considered reasonable. If the train can no longer continue and you are delayed as a result, the usual compensation claims apply—25 percent of the fare for a delay of one hour, 50 percent for a delay of two hours.
An exception may occur if, for example, a trackside fire causes the delay, in which case the train company could claim force majeure, says Naumann. “A defective air conditioning system on the train, however, is certainly not force majeure.”
With material from dpa