"It'd be so great if we took contact"

The Marines In Afghanistan On patrol in the Afghan heat:

Sweat pours off faces as Marines shift heavy weapons from one shoulder to the other. Everyone still carries all the ammunition they arrived with in the dark hours of early Thursday, because this unit has not yet exchanged fire.

The Marines walk in columns down dusty dirt roads, and every couple dozen steps they bend over at the waist to give aching shoulders a break. During frequent breaks, medics go up and down the line, looking to see if their men are drinking water.

"It'd be so great if we took contact. We'd lose so much weight," said Lance Corp. Michael Estrada, 20, of Los Angeles.

Lance Corp. Bryan Knight, a mortar man, carries one of the heaviest pack. The 21-year-old Cincinnati native weighs a slight 145 pounds (65.8 kilograms) - and his pack almost equals him.

He carries a 15-pound (6.8-kilogram) mortar base plate, four mortar rockets that weigh 10 pounds (4.5 kilograms) each, about 15 pounds (6.8 kilograms) of water and another 50 pounds (22.7 kilograms) of combat gear - ammunition, weapon and his flak jacket.

Unsurprisingly, he is drenched in sweat. "The only dry parts of my clothes are the pockets," he said.

Squatting in a lean-to made out of a camouflage poncho beside Knight was Corp. Aaron Shade, 24, of Greenville, Ohio, who hadn't realized it was Independence Day back home in the U.S.