HOUSTON (AP) _ The steering wheel is too hot to handle. The seat belt buckle can sear your skin. It's summer, and most drivers can't imagine coping without air conditioners.

Smugglers have found a way to capitalize on the need for cheap cool breezes, the U.S. Customs Service says. Freon, the now-banned refrigerant used in car air conditioners, has emerged as the No. 2 smuggling problem behind drugs along the Mexican border.

``If you look at contraband crossing the U.S.-Mexican border, we're looking at cocaine, marijuana, heroin, prescription drugs and then Freon,'' said Steve Hooper, a Customs agent.

Scientists believe Freon, used in most automobiles built before 1993, is eating away Earth's ozone layer. The black market for the gas has flourished since Jan. 1, when it became illegal to make or import it in the United States.

It can cost anywhere from $80 to $1,200 to modify a car for new coolants, said Frank Allison, executive director of the International Mobile Air Conditioning Association.

U.S. motorists can legally buy Freon made before 1996 or recycled Freon. But a dwindling supply and excise taxes have sent the price soaring. The gas is still inexpensive in Mexico and other developing countries, which may may produce Freon until 2005.

Since the ban took effect, customs agents in Texas have made more than 60 Freon seizures, confiscating 4,380 pounds, worth about $110,000.

Officials have tracked some Freon shipments that cross the U.S.-Mexico border on the way to distributors in New York. Most cans of the compound entering Texas, however, are headed for Houston or other steamy cities in the Southwest.