There's been a large drop in the number of babies and children being taken to emergency departments and paediatric assessment units in the UK since mid-April, according to a report published in the British Medical Journal.
As a result doctors are worried parents may not be getting help early enough when their little ones are unwell.
New traffic light information has been published to help remove some of the confusion for new parents. It's been written by the Royal College of Paediatrics and Child Health (RCPCH), the British Association of Perinatal Medicine, the Royal College of General Practitioners and the Institute of Health Visiting.
Consultant paediatrician Dr Yiannis Ioannou goes through the advice and explains what action you should take if you suspect your baby or child is unwell.
RED: You need urgent emergency help
If your baby has any of the following signs:
Pale, mottled (blotchy) skin which feels unusually cold.
Is stiff or rigid for a long time or makes repeated, jerky movement of arms or legs that doesn't stop when you hold them (a fit or seizure).
Is difficult to wake.
Has a rash that does not disappear when a glass is gently pressed against the skin.
Has a hot chest, face or back and is sweaty or clammy (a temperature of 38°C / 100.4°F or higher) unless this is within two days of vaccinations and there are no other signs from this section or the AMBER section below.
Is too breathless to feed, has pauses in their breathing lasting more than 10 seconds and is grunting or going blue.
Green vomit (like the colour of spinach or green washing up liquid).
Dr Yiannis says: 'You need to seek urgent help if these symptoms present themselves. Don't hesitate to go to your nearest A&E department or call 999.'
Always seek help urgently if you are frightened because your baby looks very unwell.
Difficulty breathing; including breathing fast all the time, widening their nostrils or pulling in the muscles below the ribs when breathing.
Not interested in feeding and/or looks dehydrated (dry mouth, sunken eyes, no tears, or no wet nappies in the last 8 hours).
Is increasingly sleepy or irritable (crying continuously and won't calm down).
Has yellow skin or whites of their eyes, which is quickly becoming worse.
Blood in the poo.
Very pale (white or grey) poo - keep a sample to show the doctor.
Keeps being sick.
Dr Yiannis says: 'You should contact your GP immediately to make an appointment for your baby to be seen that day, or call NHS 111.'
What to do if this doesn't work:
During the current pandemic, it may be more difficult to get advice.
Dr Yiannis says: 'If, after four hours or more, your baby hasn't improved or their condition worsened and you haven't been able to speak to either someone from your GP practice or NHS 111, you may need to take them to the nearest A&E department.'