When should I worry about my sick child?

Firstly, make sure you have a good thermometer – a tympanic digital one that goes in the ear is usually reliable. A reading of 100°F and over is classed as a fever. Acetaminophen, known by the brand name Tylenol, can be used to bring a fever down. If this isn’t sufficient, you can add ibuprofen (Advil or Motrin are well-known brands).

The fever should come down to less than 99°F and last near enough to when the next dose is due. If it’s not coming down sufficiently and not lasting, and you’ve tried both types of medication, this may be a reason to see a doctor urgently.

If your child has a fever for more than 24 hours and there’s no obvious cause – ear infection, cough, or a stomach bug – then this is a reason to seek help urgently.

If your child has a fever for 5 days or more, this is a reason to see a doctor, even if it comes down with medications.

If you have a baby less than 3 months old, you should get them checked out with a fever of 100°F or higher. You can still give them acetaminophen.

If your baby is 3 to 6 months old, see your doctor with any fever of 102°F or higher, even if acetaminophen has brought it down.

If they have a seizure with a fever, this may be a febrile convulsion. It can be scary to see but usually resolves within 5 minutes. Regardless, it’s worth getting any seizure checked out at the hospital unless they’ve had it before and you feel confident to deal with it.

Children are at higher risk of dehydration with a fever and infection, especially if they have diarrhea or vomiting, too. So, it's important to keep an eye on how much they're drinking and peeing. As a rough guide, doctors worry if they are drinking or peeing a third less than usual, and they really worry if it's half of their usual over an 8 or 12-hour period in the day.

You can probably keep a good eye on what they're drinking – make sure you don't have multiple cups, beakers, and bottles around to confuse things. With feeding, you'll know if they're breastfeeding less often or not emptying the breast as usual. They may need water top-ups between feeds.

If they are toilet trained, have a listen whether they have a good strong flow and it lasts more than a few seconds – ideally it should be pale yellow, and they could be dehydrated if it's dark and strong-smelling. With diapers, you might notice that they're lighter than usual and less frequent. Again, you know your child, so the urine shouldn't be too dark or strong smelling.

Signs of severe dehydration that warrant urgent medical attention include sunken eyes, dry lips, crying without tears, feeling cold and looking pale in fingers and toes, and babies may have a sunken fontanelle (the soft spot on the top of their head). They may seem irritable, drowsy, and difficult to keep awake. These are reasons to be concerned and seek urgent medical help.

With narrow airways and the gunkiness of a cough or cold, children can often sound congested and breathe a bit faster. There are certain signs to look out for, such as they seem to be finding it hard work to breathe and look exhausted, they are breathing much faster than usual, or taking shallow breaths every time. It may be a sign they are generally unwell, even without a cough or cold.

We get very worried if they are grunting or nodding their head to get each breath in, you can see their tummy sharply drawing in to take each breath or their ribs flare each time. These are signs that they are struggling, so make sure you see a doctor urgently.

If your child seems unwell and they look different – pale or ashen, blueish around the mouth, mottled with a web-like rash on their legs or tummy, trust your instincts and get them seen. These are all signs they could be very unwell.