A public warning message can be issused either by an organization or by an individual. As the purpose of such a message is to call on the public and alert them to a danger, convincing facts or information should be stated.

Sample:

Effects of Heroin       Heroin is produced from opium and is perhaps the most dangerous of narcotic (麻醉的) drugs that you can find on the streets today.       Dangers and Effects:       Because most heroin abusers inject the drug and often share needles, they take massive risk for HIV infection, an incurable disease which can kill. Blood pressure, pulse, breathing, and temperature all become elevated (提高). If users overdose on heroin, it reduces the number of messages the brain sends to the chest muscles. The breathing slows, and, if the dose is high enough, stops.       Common Street Names:       White girl, horse, black tar, brown sugar, smack, goods, H, junk.       Legal Status:       It is illegal to grow, process, sell or use heroin.