Understanding Fever

Fever is our body’s natural response to an invader, such as viruses or bacteria. When your immune system detects a threat, it signals the hypothalamus—the part of the brain responsible for regulating temperature—to raise your body’s set point. This creates an environment that’s less hospitable to harmful organisms.^1,2

Fever is not an illness but a symptom of an underlying condition. However, there comes a point where a fever’s intensity can cause more harm than good. So, how do you know when a fever becomes dangerously high?

What Is a Fever?

The typical body temperature in adults ranges from about 36.1°C to 37.2°C. A fever is generally considered to begin at 38°C and is classified into three categories based on its severity:

1. Low-grade fever: 38°C to 38.9°C
2. Moderate fever: 39°C to 39.9°C
3. High fever: 40°C and above

While low-grade fevers are typically benign and often helpful, higher fevers can become a cause for concern, particularly when approaching dangerous thresholds.²

Recognising When a Fever Is Dangerous

Not all fevers are the same. While a mild fever might leave you feeling fatigued or slightly uncomfortable, a dangerously high fever can lead to serious complications. Here’s how to identify when it’s time to seek medical help.

The 40°C Mark – A Warning Sign

When your body temperature hits 40°C, it’s no longer just a matter of discomfort. At this point, you might experience symptoms like severe headaches, confusion, rapid heartbeat, or extreme sweating. These are signs that your body is under significant stress. If untreated, temperatures above 40°C can lead to dehydration or worsen the underlying cause of the fever.³

41°C and Beyond – The Critical Threshold 

Temperatures exceeding 41°C are considered hyperpyrexia – a medical emergency. At this stage, the body’s proteins can denature, damaging the brain and other organs. Seizures, loss of consciousness, or even organ failure are potential risks. Immediate medical intervention is crucial.^2,3

When to Seek Medical Attention

Fever in adults

Seek help if the fever is above 40°C, persists for more than three days, or is accompanied by severe symptoms like chest pain, difficulty breathing, persistent vomiting, or confusion.^2,3

Fever in childrenW

 A fever of 38°C or higher in an infant under three months is an emergency. For older children, a fever above 39°C or persistent for more than two days warrants a call to your healthcare provider.²

Children are particularly susceptible to fevers, and their symptoms can vary:

• Focus on your child’s behaviour and overall wellbeing rather than just the temperature.
• Seek immediate medical care for infants under three months old with a fever.
• Monitor for severe symptoms like lethargy, difficulty breathing, or a persistent rash.²

Digital thermometers provide a quick, simple, and affordable way to measure body temperature for yourself or your child. Regular temperature monitoring is essential for recognising when to seek medical attention. Explore the range of Welcare and OMRON thermometers for reliable and accurate options. From basic to advanced models, these thermometers make monitoring quick and easy, helping you stay prepared and prioritise health. Always read the label and follow the directions for use.¹

Common Causes of Fever

Fever can result from various underlying conditions:

• Infections: Viral or bacterial infections, such as the flu or urinary tract infections.
• Autoimmune or Inflammatory Conditions: Disorders like rheumatoid arthritis or lupus.
• Heat-Related Illnesses: Overexposure to high temperatures can lead to hyperthermia.
• Medications: Certain drugs may cause fever as a side effect.^1,2

Fever Symptoms That Demand Urgency

In addition to high-temperature readings, watch for these symptoms:

• Stiff neck or sensitivity to light (potential signs of meningitis)
• Severe abdominal pain
• Rash that does not blanch under pressure
• Difficulty waking up or staying awake
• Laboured or rapid breathing
• Dehydration (refusing to drink and not urinating much)
• Vomiting or suffering diarrhoea
• Looks pale, weak, or lethargic
• If the fever persists after three days
• If the person is shivering or shaking uncontrollably
• Feels hot but not sweating
• Seems to be getting sicker

If any of these accompany a fever, get immediate medical attention.^2,3

Managing a Fever at Home

Home management can help alleviate discomfort and reduce risks for low-grade or moderate fevers. Here’s what to do:

1. Stay Hydrated: Drink plenty of water, herbal teas, or electrolyte solutions. Fever can lead to fluid loss, making dehydration a real risk.
2. Rest: Your body needs energy to fight off infections. Avoid strenuous activities and get adequate sleep.
3. Cool Compress: Apply a cool, damp cloth to your forehead or the back of your neck to bring down your temperature slightly.
4. Over-the-Counter Medications: Paracetamol or ibuprofen can help reduce fever and alleviate accompanying symptoms. Always follow dosage guidelines.
5. Dress Comfortably: Avoid heavy blankets or layers that could trap heat. Lightweight, breathable clothing is best.²

Prevention and Preparedness

While fevers themselves aren’t always avoidable, some preventive measures can reduce your risk of serious illness.

• Stay up to date with immunisations to protect against common infections.
• Frequent handwashing and avoiding close contact with sick individuals can minimise exposure to pathogens.
• A balanced diet, regular exercise, and adequate sleep strengthen your immune system.^2,3

Take Control of Your Health

Fevers are a natural part of life, but understanding their signs and severity is crucial. Recognising when a fever is harmless and when it signals danger can make a significant difference. Regularly reviewing first aid measures and maintaining an accessible list of emergency contacts and fully stocked first aid kit can further enhance your preparedness.

Stay informed, trust your instincts, and seek medical attention when necessary. Share this guide with your loved ones to help them confidently manage fevers. Together, we can ensure everyone is prepared to respond effectively and safely to fevers.

References:

1. MedlinePlus. Fever. Available from: https://medlineplus.gov/fever.html 
2. Better Health Channel. Fever. Victoria State Government. Available from: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/fever 
3. Queensland Health. Fever. Available from: https://www.qld.gov.au/health/condition/womens-health/infections-and-parasites/fever