In part, the concern is that they give parents a false sense of security that makes them feel more willing to put baby in less than ideal sleep environments (like putting baby to sleep on his tummy or side, sleeping in non-approved baby gear like a Rock»n Play, bedsharing / co-sleeping, letting baby sleep with a blanket or stuffed animal, etc.). (candokiddo.com)
The AAP recommends setting the thermostat to somewhere between 65 and 70 degrees Fahrenheit to maintain an ideal sleeping environment. (childdevelopmentinfo.com)
The ideal sleeping environment for an infant is one that's relatively dark, quiet, and comfortably cool. (slumbersounds.com)