Metro is breaking its ban on riders drinking water in the system on Wednesday and Thursday.
The transit agency said Wednesday morning that is lifting the ban for two days due to the forecast of extreme heat, with temperatures expected to reach into the high 90s.
The system is only allowing water, so no Gatorade or iced coffees on trains, buses or in stations.
The agency also encourages riders to use containers that "can be tightly secured" and throw away trash.
Metro also allowed water drinking last summer during a hot spell. But normally any drinking and eating are banned in the transit system.