Heat conditions at AJC Peachtree Road Race have become potentially dangerous

The race, which uses an emergency alert system, began Thursday morning with a yellow warning urging runners to exercise caution and has now been upgraded to a red warning of potentially dangerous conditions.

At the start of the race, temperatures reached 70 degrees Fahrenheit (21 degrees Celsius) and were expected to reach 90 degrees Fahrenheit (32 degrees Celsius) by the afternoon. By the end of the race, temperatures were expected to be around 80 degrees Fahrenheit (27 degrees Celsius), according to the National Weather Service.