The fireman's carry (The Debutante informs me that across the pond it's called the 'fireman's lift') is a method for one person to lift and carry a second person without assistance. It also can be used when the person being carried is incapacitated and unable to cooperate with the lifter. In essence, the lifter carries the other person (the casualty, let's say) slung across his shoulders, face down; the casualty's front leg and front arm are pulled across the lifter's chest and clasped so as to secure them in position.
A fireman's carry is useful in that it offers one of the most efficient means of transporting a person too heavy to lift comfortably in one's arms as one would a child. The weight of the casualty is distributed across the lifter's shoulders and hence does not require the lifter to use back muscles to avoid being toppled forward as in the 'child carry' position. Since the casualty is across both shoulders, the lifter's walk will jar them less severely; finally, since less muscle power is being used to remain upright (the casualty's weight is transmitted more directly to the spine and legs of the lifter) the lifter will be able to traverse longer distances before tiring.
As can be determined from the name, the technique was originally taught to firefighters. People trapped by fire will often succumb to smoke inhalation or asphyxiation, causing them to pass out without suffering physical wounds; evacuating them from the scene is paramount, and this technique is easiest. It is used by soldiers and other service members to transport wounded comrades, as well, since soldiers are typically bulky, especially if carrying equipment that it may not be feasible to remove.
Ironically, recent practice in firefighting has been to avoid the fireman's carry for a few reasons. First, in a fire, toxic gases typically rise, which is why you are advised to stay low when escaping a fire. The fireman's carry brings the casualty's airway up high, above the lifter's shoulders. Newer recommendations are for firefighters to grasp victims underneath the shoulders or by their clothing below the neck and drag them across the floor to safety. This saves the firefighter's energy since it involves lifting much less weight, and allows both the firefighter and the victim to remain low. In addition, it provides better leverage and less risk of falling; the firefighter can use the strong muscles of their legs against the floor for leverage when pulling, and the center of gravity remains quite low.
Other than falling, the main risk to the lifter of the fireman's carry is incapacitation due to muscle strain while initially lifting the casualty. The recommended technique is roughly as follows:*
- Roll the casualty onto their abdomen
- Straddle them at the hips and grasp them beneath their shoulders
- Pull them backwards and upright, transferring your grip to around their torso
- Once their knees lock (fully upright) walk slightly forward, keeping them tilted back of 'standing straight'
- Spread their feet a third of a meter or so apart with one of your own. Lift one of their wrists high above your heads (your right arm to their left, or vice versa)
- With their wrist raised, 'duck' your head under your joined arms and turn slightly towards the raised arms. This should turn you across their body.
- Bring their arm down behind your neck as you stoop so that their body bends down across your shoulders.
- Bring your other arm (the one not holding a wrist) between their legs so that your shoulder separates their thighs
- Using your leg muscles and not your back, stand up slowly. You should have their arm draped over one shoulder and their leg draped over the other with one hand holding their front wrist and the other arm holding them behind the knee.
- If possible, bring their knee and wrist together in front of your chest and use the hand locking their leg to grasp their wrist, freeing your other hand for use while moving.
It's actually a lot less complicated and a lot more intuitive than it sounds. The main thing to remember is that you want them to essentially end up lying with their weight resting on their front across both your shoulders.
This can be practiced with another person who trusts you. However, be aware that it will be different with a truly incapacitated (unconscious) person - the phrase 'dead weight' was invented to emphasize the difference in carrying someone who is unable to even unconsciously accommodate your actions by shifting their weight. Always make sure you practice over a padded surface.
* The steps for this procedure are taken from the U.S. Army's FM 21-11 (October 1988 version), First Aid for Soldiers, Appendix B Section 9, "Manual Carries."