Over the past 15 years, the population of sick neonates has changed. The average birthweight has decreased dramatically to as low as 450g while gestational age has been reduced to 22-21 weeks. These babies have totally different needs and require more complex health care. It is now time to change previous recommendations which were based on more mature neonates. In this foreword we aim to give some of the background into the ideas which lead to us starting work on new guidelines. The question was: Can the thermal condition of the baby be better monitored and investigated and, if so, how?...