Where to put a baby monitor.

The US Consumer Product Safety Commission (CPSC) is clear about it: keep monitor cords at least three feet from any part of the crib, bassinet or play yard, and never put a monitor inside the crib or on its edge. It issued that warning in 2012, after learning of seven babies and toddlers, aged 6 to 20 months, who had been strangled by monitor cords since 2002.

The cable is the part people forget. A camera can sit on a shelf well away from the crib while its cable hangs down within reach of small hands. Follow the whole cable from the camera to the socket, including for cameras mounted on the wall.

Babies reach further as they grow, and furniture moves. Check the distance again whenever the crib or the monitor does.

A monitor on a dresser or shelf, angled down, sees the whole mattress. One at mattress height mostly sees the bars. Aim for a view where you can tell at a glance which way your baby is lying and whether anything has ended up in the crib with them.

Before the first night, set the camera where you plan to leave it and look at the picture from your phone or parent unit. Can you see all four corners of the mattress? If not, raise it or tilt it rather than move it closer.

Don’t point the camera at a window. Daylight or a street lamp behind the crib turns the picture into a bright square with a dark shape in it. Face the camera away from the light, so the light falls on the crib instead.

Blind and curtain cords are a hazard of their own. The CPSC advises moving cribs and other furniture away from windows and window covering cords, preferably to another wall.

The microphone matters as much as the lens. Keep it in the open: not face-down, not behind a curtain or a soft toy, not tucked between folded clothes. A monitor that sees the crib clearly but hears it through fabric may miss the quieter sounds.

Everything above applies. A phone also needs a few things a monitor doesn’t:

• A stand. A small phone stand, or a book propped at about 45°, holds the angle all night.
• Its charger, with the cable out of reach. The camera runs all night, so the phone stays plugged in. Run the cable behind the furniture, never across the gap to the crib.
• A dim screen. The camera doesn’t need a bright screen, and a dim phone runs cooler. If it ever feels hot, move it out of direct sun and off soft fabric.
• A little light in the room. Most phone cameras have no infrared night vision, so a dim night light helps the picture.
• A good signal at the crib. Check the Wi-Fi where the phone will sit, not by the router. If it’s weak there, mobile data or a Wi-Fi extender is steadier than a faint signal.

The nursery phone checklist covers the settings that keep it running till morning: screen timeout, battery saving, background running and volume.

1. Monitor and cable at least three feet from the crib.
2. The whole mattress in view.
3. Sound coming through on your phone or parent unit.
4. Nothing in the crib but your baby: no pillows, quilts, bumpers or soft toys.