ESR1 and Fever: Critical patient (deteriorating and/or in PICU): Approx. 24 hourly: FBC, CRP, U&E, LFTs, coagulation, ferritin Other parameters guided by clinical progress Cardiac biomarkers, echocardiography in consultation with cardiology, ECGNon-critical patient with ongoing pyrexia: 24–48 hourly: FBC, CRP U&E, LFTs, ferritin*as above Echocardiography 48 hourly (in consultation with cardiology)Child improving ± defervescence: 48 hourly or pre-discharge: FBC, CRP, U&E, LFTs, ESR Consultation with cardiology prior to discharge