There's No Such Thing as Bad Weather: A Scandinavian Mom's Secrets for Raising Healthy, Resilient, and Confident Kids (from Friluftsliv to Hygge)

by Linda Åkeson McGurk

The study also showed that the ideal napping temperature was perceived as twenty-one degrees (−6°C), although many parents reported that they let their charges stay outside in temperatures as low as five degrees (−15°C) or even colder.