ATLANTA — Firefighters in Atlanta say they are already responding to multiple heat-related medical calls as extreme temperatures continue across the region.

Atlanta Fire Rescue Chief Rod Smith said one of the most common issues crews are seeing is dehydration before people even arrive at events.

“A common trend in these incidents for the patients that we’ve seen thus far is that they are already dehydrated when they get to the event,” Smith said.

Smith urged residents to begin hydrating at least a day in advance and warned that caffeinated and alcoholic drinks can speed up dehydration.

Smith’s warning comes as extreme heat continues to impact holiday events across the country. Organizers in Philadelphia canceled the city’s Salute to Independence 250 parade, which had been scheduled for Friday, due to dangerous heat conditions. The event was expected to include participants from all 50 states.

Organizers had previously attempted to shorten the parade route in response to the heat before ultimately deciding to cancel the event.

Atlanta leaders and authorities are also urging precaution ahead of the annual Peachtree Road Race as high temperatures are expected on Saturday. It is expected to begin under Red Flag conditions, officials say.

Doctors at Children’s Healthcare of Atlanta are also urging parents and caregivers to make sure children stay properly hydrated as temperatures remain high.