Heatwaves: Guidance for Pregnant Women, Infants and Children

Heatwaves: Guidance for Pregnant Women, Infants and Children

Summer is synonymous with relaxation, holidays, the sea, and outdoor play with children. In recent years, however, it has increasingly been accompanied by intense heatwaves, making it essential to understand how to protect ourselves and our children from heat-related illness.

It is now widely accepted that every summer is likely to bring increasingly higher temperatures as a result of global climate change. This reality requires us to pay particular attention to protecting vulnerable populations, including newborns, infants, children, pregnant women, older adults, and individuals taking certain medications. Special care should also be taken for outdoor workers, as well as children and adolescents participating in high-level sports under conditions of extreme heat and humidity. We should not forget our pets and stray animals, which are among the most vulnerable during periods of extreme heat.

Pregnancy during heatwaves

Exposure to high environmental temperatures during pregnancy has been associated with several maternal and fetal complications, including preeclampsia, gestational hypertension, reduced amniotic fluid volume, preterm birth, increased neonatal morbidity, lower birth weight, and even a higher risk of Sudden Infant Death Syndrome (SIDS). Experimental studies have also shown that excessive heat may impair the body's ability to synthesize proteins, potentially affecting antibody production and immune cell function, thereby increasing susceptibility to infections.

Children are particularly vulnerable to heat because their body surface area is proportionally larger relative to their body mass, their sweat glands are less efficient, they produce more metabolic heat during physical activity, and their thermoregulatory mechanisms are not yet fully developed. As a result, they are less able to dissipate excess body heat than adults.

High humidity combined with elevated temperatures further increases the risk of dehydration because it reduces the evaporation of sweat, making the body's cooling mechanisms less effective. Excessive sweating leads not only to fluid loss but also to the loss of essential electrolytes, which can further compromise the body's ability to regulate temperature.

Ιnfant/older child  dehydration symptoms

 Parents should be alert for early signs of heat-related illness, which may include:

• Unusual fussiness
• Excessive crying
• Heat rash, particularly in the diaper area

Urgent medical evaluation is required if any of the following signs develop:

• Reduced urine output or fewer wet diapers than usual
• Dry mouth or dry lips
• A sunken soft spot on an infant's head can be an important sign of dehydration and should be assessed together with other symptoms. 
• Vomit or diarrhea
• Crying without tears
• Marked irritability or difficulty being comforted

Older children may complain of:

• Nausea
• Headache
• Muscle cramps
• Muscle weakness
• Excessive thirst

They may also present with:

• Dry mouth
• Fatigue or exhaustion, especially after playing or exercising outdoors
• Dark, concentrated urine or no urine output for more than 8 hours
• Rapid breathing (tachypnea)
• Rapid heart rate (tachycardia)
• A persistently elevated body temperature that does not improve after approximately 2 hours, particularly when accompanied by the absence of sweating

The most important warning sign is any change in the child's level of consciousness. This may indicate severe heat-related illness or heat stroke and requires immediate emergency medical attention.

Warning signs include:

• Repeated vomiting
• Lethargy or unusual drowsiness
• Reduced responsiveness to stimuli
• Fainting (syncope)
• Seizures
• Confusion or altered mental status
• Loss of consciousness or coma

These symptoms should never be ignored, as they may indicate life-threatening heat stroke requiring urgent hospital treatment.

Management of  Heat-Related Illness

The management of heat-related illness depends on the child's age and the severity of dehydration.

In mild cases, the following measures are usually sufficient:

• Encourage the child to drink plenty of water.
• Move the child to a cool, shaded, or air-conditioned environment.
• Wrap the body in a cool, damp towel.
• Apply cool compresses to the forehead, neck, armpits, and groin, where large blood vessels are close to the skin.
• Remove excess clothing and dress the child in lightweight, loose-fitting garments.

For a child who has simply become overheated, water is usually adequate for rehydration. However, if dehydration is more significant—particularly after prolonged sweating, vomiting, or diarrhea—an oral rehydration solution (ORS) containing electrolytes may be appropriate.

Breastfeeding provides excellent protection against dehydration in infants, provided that breastfeeding is well established and the mother remains adequately hydrated by drinking sufficient fluids.

In more severe cases, while waiting for medical assistance:

• Move the child immediately to a cool environment.
• Turn on air conditioning or use a fan to improve air circulation (without directing the airflow straight onto an infant's face).
• Remove unnecessary clothing.
• Apply cold compresses to the body.

If the child is vomiting, place them in the recovery position (on their side) to reduce the risk of aspiration.

Do not immerse the child in ice-cold water, as this may cause rapid constriction of blood vessels, interfere with effective heat loss, and provoke shivering, which can further increase body temperature.

If a nosebleed occurs, ask the child to sit upright with the head slightly tilted forward and firmly pinch the soft part of the nose for 10 minutes without interruption.

The aim of first aid is to begin gradual cooling of the body while arranging prompt medical assessment whenever symptoms are severe or fail to improve.

When to Seek Emergency Medical Care

Heat-related illness ranges from mild dehydration and heat exhaustion to life-threatening heat stroke. Severe overheating can impair the cardiovascular, nervous, muscular, and renal systems, potentially leading to multiple organ failure and, in extreme cases, death.

Seek immediate medical attention or go to the nearest Emergency Department if a child develops:

• Altered level of consciousness, confusion, extreme drowsiness, or difficulty waking up
• Loss of consciousness or coma
• Seizures
• Persistent vomiting
• Difficulty breathing
• A body temperature of 40°C (104°F) or higher, especially if the child is no longer sweating
• Severe dehydration (very little or no urine output, dry mouth, sunken eyes, or a sunken fontanelle in infants)
• Symptoms that do not improve despite appropriate cooling measures

Severe heat stroke is a medical emergency and requires immediate hospital treatment.

Preventing heat stroke -summer safety for children

 Protection against heat-related illness is prevention.

• Check the daily weather forecast and heat warnings, and avoid outdoor activities during the hottest part of the day (approximately 12:00–16:00), particularly when humidity is high.
• Dress children in lightweight, loose-fitting, light-coloured cotton clothing and use a wide-brimmed hat when outdoors.
• Frequent breastfeeding is the best way to keep young infants hydrated during a heatwave.Whenever possible, stay in shaded areas or use an umbrella for additional protection from direct sunlight.
• Ensure adequate hydration by encouraging frequent water intake, even before children feel thirsty. Water should be the preferred drink instead of coffee, tea, soft drinks, or sugary beverages.
• Keep your home cool by closing shutters, blinds, or curtains during the hottest hours and using air conditioning or fans when necessary.
• Never leave a child or a pet unattended inside a parked vehicle, even for a few minutes. The temperature inside a car can rise to dangerous levels within minutes.
• Avoid strenuous physical activity, outdoor sports, and vigorous play during periods of extreme heat.
• Pay particular attention to overweight or obese children, as they are at increased risk of dehydration.
• Be especially cautious if a child has an acute illness such as fever, gastroenteritis, or any condition that increases fluid loss.
• In cases of heat stroke, do not administer antipyretic medications (such as paracetamol or ibuprofen) to lower body temperature. These medications are ineffective because heat stroke is not caused by infection or inflammation. Treatment relies on rapid, controlled cooling and urgent medical care.
• Children taking certain medications, including antihistamines, may be more susceptible.
• Similar caution is advised for individuals receiving antipsychotics, anticholinergic medications, diuretics, beta-blockers, insulin, or other antidiabetic medications, as these drugs may interfere with normal thermoregulation or increase the risk of dehydration.

Final Message

Education and prevention remain our most effective defenses against extreme heat.

With appropriate precautions, families can safely enjoy the Greek summer—a season of sunshine, the sea, outdoor activities, and unforgettable moments with children—while protecting their health and well-being.

Frequently Asked Questions

Can babies drink extra water during a heatwave?

For infants younger than six months who are exclusively breastfed or formula-fed, additional water is generally not required unless specifically advised by a healthcare professional. Breastfeeding may need to be offered more frequently during hot weather. Older infants who have started complementary foods can be offered small amounts of water.

How can I tell if my child is dehydrated?

Signs of dehydration include reduced urine output, dark urine, dry mouth, crying without tears, unusual sleepiness, irritability, and, in infants, a sunken fontanelle. Medical evaluation is recommended if these symptoms appear.

When should I take my child to the Emergency Department?

Seek emergency medical care immediately if your child becomes difficult to wake, has seizures, loses consciousness, has persistent vomiting, shows signs of severe dehydration, or has a body temperature of 40°C (104°F) or higher with altered mental status.

Can I give paracetamol for heat stroke?

No. Heat stroke is not caused by an infection, so antipyretic medications such as paracetamol or ibuprofen are not effective. Immediate cooling and urgent medical assessment are essential.

Can children play outside during a heatwave?

Outdoor play and strenuous physical activity should be avoided during the hottest hours of the day, particularly between 12:00 and 4:00 p.m. Children should remain well hydrated and stay in cool, shaded environments whenever possible.

Sources: World Health Organization (WHO); Hellenic National Public Health Organization (EODY)

Author: Dr. Aikaterini Dimitriou, MD
Consultant Pediatrician – Neonatologist