Summarize this article in one sentence.
While it can be fun to practice various carrying techniques with a friend, you should not attempt to perform them on an injured person without professional training. Enroll in a first aid course, nursing course, or a course on emergency or disability services if you want to be able to perform these techniques on someone who's injured or incapacitated. You should have some kind of professional certification before attempting any of these techniques.  Without professional training, it can be hard to assess the depth of someone's injuries. You may be unsure which carry to use if you're unable to tell if it's safe to move someone in a particular position. Carrying someone safely requires a great deal of practice and guidance. You should practice carrying someone with the supervision of a professional, who can correct your form and provide tips. Professional training can help you learn how to conduct yourself safely during an emergency. If someone is injured or disabled, don't jump to performing one of the above techniques. Ask that person how he should be moved first, and check if the person has any special needs or considerations you should keep in mind. An injured or disabled person may also be waiting on professional services, and may not need the help of you and your partner. It's always better to ask first. If a person has life-threatening injuries, call 9-11 immediately. Do not attempt to move the person unless you are advised by a 9-11 dispatcher to do so.

Summary:
Get professional training before attempting an actual rescue. Ask how you can help first. Call 9-11 in the event of life-threatening injuries.