A Williamson County man was burned Thursday while trying to siphon gasoline.

Paramedics say he was trying to siphon gas from his vehicle when everything went up in flames on Justin Leonard Road, just outside of Round Rock.

The man told EMS workers he could not get enough suction to siphon the gas, so he attached his vacuum cleaner. That led to a blast and flash fire, severely injuring the man.

"It looked to be about 30 percent of his body was burned -- 3rd degree burns to his hands," said Gunther Vonseltmann, Round Rock EMS.

The man was taken by STARflight helicopter to the burn center at Brooke Army Medical Center in San Antonio for treatment.

No one else was hurt.