To give rescue breaths without a mask, you seal your mouth directly over the person’s mouth (or mouth and nose for an infant), pinch their nose shut, and blow steadily for about one second until you see their chest rise. This classic mouth-to-mouth technique remains effective and is recommended when a barrier device isn’t available, especially in situations like drowning or opioid overdose where breaths can be lifesaving.
Opening the Airway First
Before any breath will reach the lungs, the airway needs to be open. An unconscious person’s tongue can fall backward and block the throat, so positioning the head correctly is the single most important step. The technique is called head-tilt/chin-lift, and it takes about two seconds.
Place one hand on the person’s forehead and gently tilt the head backward. With your other hand, place two or three fingertips under the bony part of the chin and lift it upward. For an adult, tilt the head past neutral into a “sniffing” position, as if they were sniffing a flower. For an infant, keep the head in a neutral position only, because over-tilting can actually kink their small airway. Be careful not to press into the soft tissue under the jaw, which can compress the airway instead of opening it.
If you suspect a neck or spinal injury, a jaw thrust is the alternative. Place your hands on either side of the head, put two or three fingers behind the angle of the jawbone on both sides, and gently push the jaw forward and upward without moving the head or neck.
Mouth-to-Mouth on an Adult
With the airway open, pinch the person’s nose closed with the hand that’s on their forehead. Take a normal breath (not an exaggerated deep one), place your mouth over theirs to create a complete seal, and blow steadily for one second. Watch the chest as you blow. You should see it visibly rise, similar to a normal breath. Then lift your mouth away and let the air escape on its own before giving a second breath.
The standard pattern is 30 chest compressions followed by 2 rescue breaths, repeated in cycles. The 2025 American Heart Association guidelines reaffirm this 30:2 ratio for CPR performed by trained rescuers. Each breath should last about one second and produce visible chest rise.
If the first breath doesn’t make the chest rise, don’t just blow harder. Re-tilt the head, reposition the chin lift, and check your seal before trying the second breath. If neither breath produces chest rise, something may be blocking the airway. Move on to compressions, which can help dislodge an obstruction, and check the mouth for visible objects before your next set of breaths.
Why One Second Matters
The one-second breath duration isn’t arbitrary. When you blow air into someone who doesn’t have a breathing tube protecting their airway, some of that air can travel down the esophagus into the stomach instead of the lungs. This is called gastric inflation, and it creates real problems: a stomach full of air increases the chance of vomiting, and vomit in the airway during CPR can be fatal.
Research modeling the physics of rescue ventilation found that breaths shorter than one second require too much pressure, which forces air past the muscle at the top of the stomach. Breaths longer than one second keep that pressure applied for too long, with the same result. One second hits the sweet spot, delivering enough air to the lungs while minimizing stomach inflation. Blow gently and steadily, using only enough force to see the chest rise. Think of it as a firm, normal exhale, not inflating a balloon.
Technique for Infants and Small Children
For a baby under one year old, the approach changes in a few important ways. An infant’s face is small enough that you can cover both the mouth and nose with your mouth at once, creating a seal over both. If you can’t manage that, seal your mouth over just the nose and gently close the lips to prevent air from escaping, or cover just the mouth and pinch the nose.
Use only a small puff of air, just enough to see the tiny chest rise. Blowing too hard can damage an infant’s lungs. Keep the head in a neutral position rather than tilted back. For children roughly ages one through puberty, use the same head-tilt/chin-lift as adults but with a gentler tilt, and blow with less force than you would for an adult.
One key difference: for infants and children who are unresponsive and not breathing, start with 5 initial rescue breaths before beginning chest compressions. This differs from the adult sequence, where compressions typically come first.
When Rescue Breaths Are Most Critical
Hands-only CPR (compressions without breaths) has become the standard recommendation for bystanders witnessing a sudden cardiac arrest in an adult. In those cases, the blood still contains oxygen for several minutes, and keeping it circulating with compressions is the priority. But there are scenarios where rescue breaths become essential.
Drowning is the clearest example. The heart stops because the body ran out of oxygen, not because of an electrical problem in the heart. CPR for a drowning victim follows the traditional airway-breathing-circulation sequence, starting with 5 rescue breaths before compressions because water in the airways makes initial ventilation more difficult. Chest compressions alone are not recommended for drowning. The same principle applies to opioid overdoses, choking, and any situation where the person stopped breathing before their heart stopped.
Children and infants in cardiac arrest also benefit significantly from rescue breaths, since pediatric cardiac arrest is more commonly caused by breathing failure than by a heart rhythm problem.
Addressing Infection Risk
Concern about disease transmission is one of the main reasons people hesitate to perform mouth-to-mouth on a stranger. The actual risk is low but not zero. Saliva can carry viruses like herpes simplex (the virus behind cold sores) and cytomegalovirus, both of which spread through direct oral contact. Respiratory infections can also theoretically transfer during close face-to-face contact.
That said, documented cases of serious disease transmission from CPR rescue breaths are extremely rare in medical literature. If visible blood, vomit, or sores are present around the person’s mouth, you can focus on hands-only CPR (compressions at a rate of 100 to 120 per minute) while waiting for emergency responders who carry barrier devices. For someone you know, such as a family member or child, the benefits of rescue breaths in a life-threatening emergency far outweigh the small infection risk.
Quick-Reference Steps
- Position the person: flat on their back on a firm surface.
- Open the airway: hand on forehead, tilt head back, lift chin with fingertips.
- Seal and pinch: pinch the nose shut, place your mouth fully over theirs.
- Blow for one second: a steady, normal exhale until the chest visibly rises.
- Release and repeat: lift your mouth, let air escape, give a second breath.
- Continue the cycle: 30 compressions, then 2 breaths, repeating until help arrives or the person starts breathing.
For infants, cover both mouth and nose with your mouth, use gentle puffs, and begin with 5 initial breaths. For drowning victims of any age, prioritize those initial 5 breaths before starting compressions.