Officials sent players, coaches and staff members off the field at the start of the fourth quarter. The Jaguars were leading 17-14.
They returned 23 minutes later, then had a 10-minute warmup before beginning the final quarter.
Public address announcers asked fans to seek shelter during the delay.
The game was the hottest in Jacksonville's franchise history. It was 93 degrees in the third quarter, with 59 percent humidity and a heat index of 105 degrees.
The stifling heat also brought some rain in the third quarter. Lightning followed a few minutes later.
The temperature dropped to 78 degrees after the thunderstorm.