Heat-Induced Seizures in Children

Heat-Induced Seizures in Children

Heat can trigger seizures. In a child with epilepsy, a sharp rise in core body temperature lowers the seizure threshold, and dehydration and electrolyte loss make a seizure more likely still. In a child with no seizure history, heat stroke itself can cause a seizure — and that is a medical emergency. In Arizona, where summer surface temperatures routinely exceed 110°F, this is one of the most common questions Dr. Tamara Zach MD is asked.

Can heat cause seizures?

Yes, through two different mechanisms. In children who already have epilepsy, heat is a trigger: raised core temperature increases neuronal excitability, and the dehydration that comes with it changes sodium and potassium levels that neurons depend on to stay stable. In children without epilepsy, extreme heat is a cause: once core temperature passes roughly 104°F, heat stroke can produce a seizure directly as part of central nervous system injury.

Can heat stroke cause seizures?

Yes. Seizure is a recognized feature of heat stroke and marks it as severe. Heat stroke is defined by a core temperature at or above 104°F together with central nervous system dysfunction — confusion, slurred speech, loss of consciousness, or seizure. A seizure from heat stroke is not epilepsy; it is a sign the brain is being injured by heat, and it requires immediate emergency cooling and hospital care.

Can heat exhaustion cause seizures?

Heat exhaustion on its own rarely causes a seizure. Heat exhaustion involves heavy sweating, weakness, nausea, headache, and a core temperature under 104°F, with normal mental status. If a child having heat symptoms seizes or becomes confused, the condition has progressed past heat exhaustion to heat stroke and should be treated as an emergency. In a child who already has epilepsy, however, the dehydration of heat exhaustion can lower the seizure threshold enough to provoke a breakthrough seizure.

Heat-induced seizures in children with epilepsy

Parents of children with epilepsy often notice a seasonal pattern to breakthrough seizures, and there are several reasons for it:

• Dehydration. Fluid loss shifts sodium levels and can change how anti-seizure medication is concentrated in the blood.
• Disrupted sleep. Hot nights fragment sleep, and sleep deprivation is one of the strongest seizure triggers in children.
• Missed or mistimed doses. Summer travel and schedule changes are a frequent and correctable cause of breakthrough seizures.
• Medication heat exposure. Anti-seizure medication left in a car or a beach bag can degrade; most should be stored below 77°F.
• Photosensitivity. A minority of children are sensitive to sunlight flickering through pool water, car windows, or trees.

Is this the same as a febrile seizure?

No. A febrile seizure is driven by fever from infection, typically in children between 6 months and 5 years, and is generally benign. A heat-related seizure comes from external heat load rather than infection, can happen at any age, and in the case of heat stroke signals a life-threatening emergency. The distinction matters because the treatment is different: fever is managed with medication, while heat stroke is managed with rapid physical cooling. If your child has had a fever-associated seizure, see our page on febrile seizures in children.

What to do during a heat-related seizure

1. Move the child to shade or air conditioning immediately.
2. Lay them on their side to protect the airway. Do not put anything in their mouth.
3. Begin cooling — remove excess clothing, apply cool water or cool packs to the neck, armpits, and groin.
4. Time the seizure. Call 911 for any seizure lasting more than five minutes, any first-time seizure, or any seizure with signs of heat stroke.
5. Do not give fluids by mouth until the child is fully alert.

Preventing heat-triggered seizures in Arizona

For families managing epilepsy through an Arizona summer, Dr. Tamara Zach MD recommends scheduling outdoor activity before 9 a.m. or after 7 p.m., maintaining consistent hydration rather than catching up after symptoms start, protecting sleep schedules through travel, keeping medication out of hot cars, and building a written seizure action plan that camp staff, coaches, and caregivers have a copy of.

When to see a pediatric neurologist

Schedule an evaluation if your child has had a seizure of any kind for the first time, if a child with known epilepsy has more breakthrough seizures in summer, or if you are unsure whether an episode was a seizure. Dr. Tamara Zach MD provides comprehensive evaluation including EEG testing and ongoing management of pediatric epilepsy at Rose Medical Pavilion.