Florida Gas Transmission on Tuesday issued its latest in a string of warnings to natural gas shippers on Tuesday as hot weather was again expected to boost demand on its pipeline system.

To maintain system integrity, the company issued an overage alert at 25 percent tolerance, meaning shippers must stay within 25 percent of scheduled volumes, the company said in a Web site posting.

Alerts, also called critical days, require natural gas shippers to adhere carefully to scheduled quantities. An overage alert signals that taking excess quantities off line would be harmful.

Florida Gas regularly issues shipper alerts as temperatures in the state vary extremely from normal, boosting gas and power demand as customers crank up air conditioners in the spring and summer months and heaters in the winter.

Extreme heat was expected to continue across the Southeast through at least Wednesday, with high temperatures continuing to climb above 100 degrees (Fahrenheit), according to forecaster AccuWeather.

The 5,000-mile Florida Gas Transmission pipeline runs from southern Texas to southern Florida, with a mainline capacity of 2.1 billion cubic feet per day.