Trains are struggling in the Sydney heat this afternoon, with services disrupted across the network.
Buses are currently replacing trains between Blacktown and Mulgrave on the T1 Western Line.
The T5 Cumberland Line is also affected.
According to the Transport Management Centre, high temperatures are affecting infrastructure at Schofields.
A shuttle train service is currently operating between Mulgrave and Richmond.
For anyone about to jump on a train, it is advised that you allow plenty of time for your trip, listen to announcements and check indicator boards.