To inform the feasibility of conducting a study to test different temperature thresholds at which clinicians deliver interventions to reduce fever (i.e. antipyretic interventions) in critically ill children with fever due to infection.

Fever (high temperature) is a normal bodily response to an infection, which has shown to have a beneficial effect in humans with chickenpox, malaria and rhinovirus infections. In children it has been recommended by the National Institute for Health and Care Excellence not to cool down the child using drugs or physical methods such as a cooling mat, with the sole aim to reducing the child's temperature. However, this recommendation is not aimed at the management of critically ill children, to which there is uncertainty around use of cooling interventions when considering the advantages of a fever in defending the body against viruses and bacteria during critical illness, and weighing that up with the possible negative physiological consequences of a high fever e.g. increased metabolic rate.

Observational studies show that the treatment of fever in critically ill children is inconsistent. There is a lack of robust data to guide antipyretic intervention, with clinicians usually starting fever management at around 37.5°C. Evidence is emerging that fever may be beneficial in critically ill adults. Due to the physiological differences between adults and children there is an important need to evaluate whether a different approach to fever management in critically ill children may also be beneficial.

Prior to conducting a large, expensive, randomised clinical trial (RCT) to evaluate whether a higher temperature threshold in starting treatments to cool down the child would be beneficial, we are conducting three studies to know if it is possible for us to test key outcome measures as a result of testing different temperatures thresholds for antipyretic management.

The Fever Observational Study is one of these studies, with the aim of identifying: the potential population that would be eligible for the proposed definitive trial, current temperature threshold(s) for fever management, and to describe the characteristics of outcome measures with the intention of deciding on a main measure to see which treatment method was more successful.

Inclusion Criteria:

unplanned PICU admission referral requiring PICU admission to a participating unit

All unplanned admissions to a PICU