PHILADELPHIA (WPVI) -- Amtrak says commuters could encounter delays between Philadelphia and New York City due to the hot weather.
The rail line said Friday that heat restrictions have been put into place.
According to Amtrak's website, a heat restriction means locomotive engineers must operate at slower speeds than normal.
That's because the rails and wires could expand when they get too hot.
"Speed reductions are based on the rail temperature, not the ambient (air) temperature. That data ensures we're only issuing heat restrictions when necessary," Amtrak's website reads.
Amtrak recommends that commuters check online service alerts or call/text 1-800-USA-RAIL (1-800-872-7245) for updates.