Belgian railway operator SNCB has cancelled several rush-hour trains on Friday as temperatures are expected to reach 37°C or 38°C in parts of the country.
Several P trains, which provide additional services during the morning and evening rush hours, will not run due to the extreme heat, SNCB announced on its website.
The railway operator is also advising passengers to avoid travelling during peak hours where possible and to carry water.
P trains generally make only one journey in the morning and another in the evening, meaning they remain parked outside during the hottest part of the day and can accumulate significant heat.
Many of these trains are also older and do not have air conditioning. When temperatures become too high, SNCB says they can no longer safely carry passengers and staff.
Reducing the number of trains in service also lowers the risk of a train becoming stranded on the tracks during the extreme heat.
High temperatures can cause problems for the railway infrastructure itself. Overhead electrical wires can sag in the heat, increasing the risk of damage as trains pass.
Temperatures above 35°C can also cause rails to expand, increasing tension and potentially deforming the tracks.
An orange heat warning is in force across all Belgian provinces except West Flanders on Friday, with temperatures expected to reach as high as 38°C locally.
