Chris Rhoad, from left, Shawnte Boggs and Canan Aker, all of Lawrence, practice using a defibrillator at the American Red Cross, 2518 Ridge Court. Class instructor Kristy Wempe says the defibrillators are already found in some district schools and government buildings and are being installed in all Lawrence schools.

Automated external defibrillators are more simple to use than their name suggests.

“You just hook it up, and it really does the work for you,” says Kristy Wempe, health and safety marketing director for the Douglas County chapter of the American Red Cross. “You just have to follow the prompts.”

Defibrillators, also known as AEDs, have long been used by emergency responders in hospitals and on ambulances. But the devices, which restore normal heart rhythm, are appearing in an increasing number of settings, from schools to workplaces.

That means you might be in a position to have to use one. Here are the basic steps, according to Wempe:

1. Turn it on. Make sure the machine is properly charged. Some models will turn on as soon as the case is opened.

2. The AED will prompt the user to attach pads to the victim. Most devices have diagrams on the pads to show where to place the pads, which should be on the upper right and lower left side of the victim’s chest.

3. Once the pads are attached to the victim and machine, the user must analyze the heart’s rhythm. Some devices will automatically begin to analyze. Other devices may prompt the user to press a button to start this process. AEDs will only shock a victim when they have detected a certain type of rhythm.

4. Once the defibrillator locates the rhythm, it will indicate that it is ready to shock. Shocking is the treatment given to the victim to briefly stop the heart, allowing it to “reset” to an effective rhythm.

5. The device will advise users and bystanders to stand back for their safety. The primary user of the device should also reiterate the warning for bystanders to stand back. If a bystander or rescuer is in contact with the victim when the treatment is delivered, it can be very harmful to them.

6. Once the rescuer has determined that everyone is clear, they can deliver the treatment by pressing a button on the machine.

7. Treatment will be delivered, and the device will again analyze for a heart rhythm. Many machines deliver up to two treatments in a session.

8. The device may instruct the user to perform CPR if no rhythm is detected. After about two minutes of CPR, the device may reanalyze the heart rhythm.

Wempe says the pads should remain on the victim with the machine turned on until emergency personnel arrive.

If a bystander witnesses a person collapse and the victim is unresponsive and shows no signs of life, then an AED should be used as quickly as possible.

“Statistics show that each minute defibrillation is delayed, it decreases that persons chance of survival by 10 percent,” she says.

But if that bystander discovers a person lying unconscious on the floor and did not witness the collapse, it is suggested that CPR be attempted for 2 minutes before applying a defibrillator.