Can Ibuprofen Cause Too Low Temperature? A Look at the Rare Risk of Hypothermia

October 14, 2025 •

4 min read

While ibuprofen is a common and effective fever reducer, some case reports and studies, particularly involving children, have highlighted a potential adverse reaction: hypothermia. Defined as a core body temperature below 35°C (95°F), this side effect is rare but demonstrates the importance of understanding the medication's effects beyond its intended purpose.

Quick Summary

Ibuprofen, a common antipyretic, can, in rare instances, cause abnormally low body temperature (hypothermia), especially in children. The risk is linked to its mechanism of action and potentially improper dosage. Though uncommon, it is a serious concern, requiring vigilance and proper medical guidance.

Key Points

Rare Side Effect: Ibuprofen can, in very rare instances, cause a dangerously low body temperature, a condition called hypothermia.
Higher Risk in Children: The risk of ibuprofen-associated hypothermia is more frequently reported in young children due to their physiological differences and developing thermoregulatory systems.
Overdose Increases Risk: Taking more than the recommended dose of ibuprofen can increase the likelihood of experiencing a sudden and significant drop in body temperature.
Hypothermia Symptoms: Key signs to watch for include shivering, confusion, lethargy, cold skin, and a weak pulse.
Seek Medical Attention: If signs of hypothermia appear, especially after using ibuprofen, it is crucial to seek immediate medical help.
Mechanism of Action: Ibuprofen reduces fever by inhibiting prostaglandins, which can, in rare cases, cause an overcorrection of the body's internal thermostat.

Understanding Ibuprofen's Role as an Antipyretic

Ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), is widely used to relieve pain, reduce inflammation, and lower fever. Its effectiveness as an antipyretic, or fever reducer, stems from its ability to inhibit cyclooxygenase (COX) enzymes. These enzymes are responsible for the synthesis of prostaglandins, which are key mediators in the body's fever response. During an infection, the body's internal thermostat, located in the hypothalamus, is reset to a higher temperature by these prostaglandins. By blocking their production, ibuprofen helps to reset this thermostat back to a normal range, allowing the body's temperature to decrease.

The Rare Connection Between Ibuprofen and Hypothermia

For most people, this temperature regulation mechanism works as intended. However, in rare cases, the body's temperature can drop below the normal range, a condition known as hypothermia. A core body temperature below 35°C (95°F) is considered hypothermic. The connection between ibuprofen and hypothermia is not a new discovery; spontaneous adverse drug reaction reports and clinical studies have documented this risk, especially in the pediatric population.

Documented Case Reports: Studies have analyzed cases of ibuprofen-associated hypothermia. For instance, a review of Italian databases found several reports of hypothermia linked to ibuprofen use in young children. A specific case involved a young child who developed significant hypothermia after receiving both ibuprofen and paracetamol.
Mechanism Speculation: The exact mechanism for this adverse reaction is not yet fully understood. One theory, especially in overdose cases, is that the rapid lowering of core temperature could be related to a central nervous system depression caused by the medication. In children, physiological and anatomical differences, such as a higher body surface area to mass ratio and a less mature thermoregulatory system, may make them more susceptible to this effect.

Risk Factors for Ibuprofen-Induced Hypothermia

While not a common side effect, several factors may increase the risk of an individual experiencing an abnormally low temperature after taking ibuprofen:

Age: Young children, particularly those under 5 years old, appear to be at a higher risk. Their bodies are generally more sensitive to medication and their thermoregulatory systems are still developing.
Overdose: Taking more than the recommended dose of ibuprofen, either accidentally or intentionally, can increase the likelihood of a severe drop in body temperature. Always follow the dosing instructions on the packaging or as prescribed by a healthcare professional.
Combination with Other Antipyretics: Co-administering ibuprofen with other fever-reducing medications like paracetamol (acetaminophen) can sometimes lead to a more pronounced temperature-lowering effect. This is particularly risky if dosages are not carefully monitored.
Underlying Health Conditions: Individuals with certain pre-existing conditions, especially those affecting metabolic rate or neurological function, might be more vulnerable to a significant drop in temperature.

Comparison: Ibuprofen vs. Paracetamol and Low Temperature Risk

When considering fever reducers, it is helpful to compare the risk profiles, though the risk of significant hypothermia is rare for both when used correctly. The key difference lies in the reported cases and the specific population most affected.


Feature	Ibuprofen	Paracetamol (Acetaminophen)
Mechanism of Action	Inhibits COX enzymes, reducing prostaglandin synthesis.	Acts on the hypothalamus to regulate temperature, though the exact mechanism is not fully understood.
Associated Hypothermia	Documented cases, particularly in children.	Fewer documented cases linked directly to hypothermia, especially at therapeutic doses.
Main Risk Population	Primarily noted in children, though rare adult cases can occur.	Risk appears generally lower, though still possible in cases of overdose or improper use.
Effect on Temperature (Adult Study)	In one study, had no statistically significant effect on body temperature compared to placebo. (Note: This finding contrasts with pediatric case reports).	In the same study, a small but statistically significant short-term reduction compared to placebo was noted.

How to Recognize and Respond to Low Temperature

It is important to differentiate between a slight temperature drop after a fever breaks, which is normal, and clinical hypothermia. Seek medical attention if you or someone else displays signs of hypothermia, especially in conjunction with ibuprofen use.

Common Signs of Hypothermia:

Shivering (this may stop as hypothermia worsens)
Confusion, slurred speech, or unusual behavior
Lethargy, drowsiness, or exhaustion
Cold, pale, or waxy-looking skin
Weak pulse and shallow breathing

What to Do if Hypothermia is Suspected:

Seek Medical Help: Contact a healthcare professional or emergency services immediately.
Warm the Person: Move the individual to a warm place. Wrap them in blankets, and use warm compresses on the neck, chest, and groin area.
Remove Wet Clothing: If their clothes are wet, remove them carefully and replace with dry garments.
Offer Warm Fluids: If the person is conscious and able to swallow, offer a warm, non-alcoholic, and non-caffeinated drink.
Avoid Direct Heat: Do not use direct heat sources like hot water or heating pads, as this can cause burns.

Conclusion

While the widespread use of ibuprofen as a fever reducer is safe and effective, the potential for it to cause an abnormally low temperature, or hypothermia, is a documented but rare side effect. This risk appears to be more pronounced in young children, likely due to their less developed thermoregulatory systems and different physiological makeup. It is crucial for parents and caregivers to administer the correct dose based on age and weight and to be vigilant for any signs of hypothermia. If an overdose is suspected or a significant drop in temperature occurs, immediate medical attention is necessary. Staying informed about both the benefits and potential risks of any medication is key to ensuring health and safety.

For more information on the side effects of ibuprofen, consult a reliable source such as the Advil product information page or speak with your doctor.

Frequently Asked Questions

Ibuprofen lowers body temperature by inhibiting cyclooxygenase (COX) enzymes, which in turn reduces the production of prostaglandins. Prostaglandins are responsible for resetting the body's internal thermostat to a higher temperature during a fever, so by blocking them, ibuprofen allows the temperature to return to normal.

Yes, a slight decrease in body temperature as a fever breaks is a normal and expected effect of taking an antipyretic like ibuprofen. The concern for hypothermia arises when the temperature drops to a dangerously low level (below 35°C or 95°F).

The signs of hypothermia can include shivering, confusion, slurred speech, lethargy, feeling cold to the touch, and shallow breathing. If these symptoms appear, particularly after taking ibuprofen, it is important to seek medical advice.

Children are considered more susceptible because of their different physiological makeup, such as a higher surface area to mass ratio and a less mature thermoregulatory system. This can make them more sensitive to medication effects that alter body temperature.

While the risk is more commonly documented in children, adults could potentially experience this side effect, especially in cases of overdose or if they have underlying health conditions that affect temperature regulation. The general risk is considered very low.

If you suspect hypothermia, seek immediate medical attention. While waiting for help, move the person to a warm environment, remove any wet clothing, and cover them with warm blankets.

Yes, combining ibuprofen and paracetamol (acetaminophen) can increase the risk of a significant temperature drop. Some case reports of hypothermia have involved children who received both medications, highlighting the importance of careful dosing when using combination therapy.