Trinity Metro and DART warn TRE trains will be operating at reduced speeds Monday afternoon due to excessive heat.
In the past, the TRE said when temperatures climb above 100 degrees trains are kept below 65 mph, which is up to 20 mph slower than normal.
The reason is that the intense heat can cause additional stress on the train's diesel engines and make it difficult for the radiator to cool them. The trains are slowed down as a precaution to keep them from overheating.
Riders are warned to expect delays of 10-20 minutes during the afternoon.