A low-grade fever is considered to be 37.5°C - 37.9°C / 99.5°F - 100.22 °F, while a proper fever starts at 38°C / 100.4 °F. Your temperature can be raised for many reasons such as, an infection heatstroke, inflammation in the body and medical conditions such as hyperthyroidism where the thyroid gland is overactive.

Generally, a low temperature will be 35.1°C - 36.0°C / 95.18°F – 96.8°F, while 35°C / 95 °F or below is considered to be a dangerously low temperature. Some people can naturally have a low body temperature, but other times it could be a sign that something is wrong.

Some more worrying causes are:

· Sepsis, a dangerous infection that causes internal damage.

· Hypothermia, when your body temperature lowers to a dangerous level due to being exposed to extremely cold temperatures.

· Hypothyroidism, where the thyroid gland is underactive.

This can vary, but common symptoms may include:

· Feeling hot and sweating

· A high temperature of 38.0°C / 100.4 °F or higher

· Chills and shivering

· Feeling unwell

· Loss of appetite

· Reduced energy levels

· Dehydration

· A rash that fades under pressure.

· Acting differently e.g., not playing like usual.

· Not drinking enough.

· They are dehydrated, some signs could include weeing less than usual or sunken eyes.

· Shaking and shivering with a high temperature.

· A fever that lasts 5 days or longer.

· A baby that’s under 3 months old with a temperature of 38.0°C / 100.4 °F or higher.

· A child aged between 3 – 6 months with a temperature that is above 39.0°C / 102.2 °F.

· If your parental instinct is telling you that something is wrong, please contact your GP or ring NHS 111.

· If you’re experiencing dehydration and are struggling to manage it (only passing small amounts of dark urine or are experiencing excessive thirst).

· A new, severe pain.

· Experiencing a fever for 5 days that’s not getting better or is getting worse.

· You’ve recently travelled overseas.

· If you have other medical conditions (or take medicine) that could make you susceptible to complications or more severe infections. For example, having an organ transplant or a suppressed immune system.

· They appear very unwell.

· They look pale, blotchy or blue.

· They’re not responding to you like they usually would.

· They’re having difficulty staying awake and seem lethargic.

· They’re breathing very quickly or noisily or are struggling with their breathing in general.

· They have a rash that doesn’t fade under pressure (you can do the glass test to find this out).

· They’re experiencing neck stiffness.

· They’re sensitive to light.

· They have unusually cold hands and feet.

· They’re crying weakly at a high pitch that sounds different to their usual cry.

· They’re inconsolable.

· They appear to be confused.

· They appear to be having a seizure for the first time.

· A temperature that is 40.0°C / 104° F or higher.

· You feel poorly.

· You have a fever.

· You feel lethargic, faint or lightheaded.

· You’re experiencing shortness of breath.

· You feel confused.

· You have a new severe headache along with vomiting +/- a non-fading rash +/- neck stiffness +/- light sensitivity or changes in vision.

· You are experiencing symptoms that you believe to be life-threatening.