Festering Fear

"MEDIIIIC!!!"
An unearthly call that echoes through the endless space surrounding him as he runs. His bones are purpose-built, muscles task-dedicated, mind specifically trained for this. With great strides his boots pound into the ground, one after the other, propelling his gear-laden person forward. Faster and faster he runs, a slow thumping pound in his ears.
He reaches a wall with poor means of scaling, and no way around. Furrowing his eyebrows and pressing his lips, he throws himself against it, clinging to the few niches as he struggles against his heavy vest, pouches, and packs to pull himself up to the next. Without looking down, he reaches the top and drops over, tumbling across the ground to continue his sprint. The pounding continues, steadily increasing in frequency.
Suddenly he stands at the bank of a rushing river, the opposite bank impossibly far away. Taking a deep breath, he wades in as the water rises higher and higher towards his chin. Struggling to keep his balance on the invisible ground he uses to brace against the strong current, he drops his largest pack and doubles his pace to the shore. Slowly speeding up, the thumping drowns out his own cutting breaths.
A figure suddenly emerges from behind cover, striking an aiming pose while looking directly at him. Close enough to engage, he throws himself out of the bullet's path and strikes at the man, drawing his knife and plunging it into the figure's torso. Without recovering his weapon he dashes away from the falling man. The pounding now outstrips his own footfalls.
The ground just ahead of him explodes with dust and fire, knocking him off balance. Not even hesitating, he catches his fall with one hand and throws himself onward, passing the crater before the dirt even finishes falling. His head is about to explode from the intensity of the thudding against his ears.
Just a stone's throw away is a group of huddled soldiers in matching uniforms. Adrenalin fills his arteries and he powers his burning legs onward as one beckons frantically. Nearing them, some part to reveal a bloody figure in their midst. Apprehension slowly turns to panic as he can almost see the face of the wounded warrior. The moment he reaches the scene the heartbeat suddenly stops with his own.
A sharp intake of breath and the feeling of cold sweat clinging to the inside of a sleeping bag jolt the medic to life as the sounds of nighttime wildlife echo beyond his canvas walls.