Dehydration, mineral loss, sun glare, and heat exhaustion can all cause heat-induced headaches and migraine.

Severe headaches and migraine are not uncommon, affecting 20 percent of women and nearly 10 percent of men living in the United States.

Headaches seem to be even more likely to happen in the summer months when temperatures are elevated. Headache frequency may rise when it’s warmer out for a number of underlying reasons, including dehydration, environmental pollution, heat exhaustion, and even heat stroke being more prevalent as temperatures rise.

Heat itself may be a trigger for headaches, although research results vary.

A heat-induced headache may feel like a dull, thudding ache around your temples or in the back of your head. Depending on the cause, a heat-induced headache may escalate to a more intensely felt internal pain.

Heat-induced migraine

Migraine affects approximately 18% of women and 6 percent of men in the United States, and they’re more common in the warmer months.

A heat-induced migraine is not the same as a heat-induced headache, because the two have some differences in their symptoms. What heat-induced migraine and headaches have in common is that they’re both triggered by the way that heat affects your body.

A heat-induced headache may not be caused by hot weather itself, but by the way your body responds to heat.

Weather-related triggers of headache and migraine include:

Heat-induced headaches can also be caused by dehydration. When you’re exposed to higher temperatures, your body needs more water to make up for what’s being lost as your body sweats. Dehydration can trigger both a headache and a migraine.

Weather conditions can also cause changes in your serotonin levels. These hormonal fluctuations are a common migraine trigger, but they can cause a headache, too.

Prolonged exposure to high temperatures also puts you at risk for heat exhaustion, one of the stages of heat stroke.

Headache is a symptom of heat exhaustion. Any time you’re exposed to high temperatures or spend a long time outside under the hot sun and get a headache afterward, you should know that heat stroke is a possibility.

Symptoms of a heat-induced headache can vary according to the circumstance. If your headache is triggered by heat exhaustion, you will have heat exhaustion symptoms in addition to your head pain.

Heat exhaustion symptoms include:

  • dizziness
  • muscle cramps or tightness
  • nausea
  • fainting
  • extreme thirst that won’t subside
Medical emergency

Heat exhaustion is a medical emergency and can lead to heat stroke if it’s not treated. Seek immediate medical help.

If your headache or migraine is related to heat exposure, but not connected to heat exhaustion, your symptoms may include:

  • a throbbing, dull sensation in your head
  • fatigue
  • sensitivity to light
  • dehydration

If heat tends to trigger your headache or migraine, you can be proactive about prevention.

If possible, limit your time outside on hot days, and protect your eyes with sunglasses and a hat with a brim when you venture out. Exercise indoors in an air-conditioned environment if you’re able to do so.

Drink extra water as temperatures start to rise, and consider drinking sports drinks to replace your electrolytes.

If you already have a headache, consider home remedies like:

Over-the-counter acetaminophen (Tylenol) and ibuprofen (Advil) can also be used as needed for pain relief.

Mild headaches and migraine caused by dehydration or changes in the weather will usually go away on their own within one to three hours. But there are times when a heat-induced headache is a sign you need emergency care.

Seek medical help right away if you have a heat-induced headache with any of the following symptoms:

  • nausea and vomiting
  • high fever (103.5 degrees or higher)
  • a sudden spike in pain levels or intense pain in your head
  • slurred speech, confusion, or disorientation
  • pale or clammy skin
  • extreme thirst or lack of appetite

If you don’t have emergency symptoms, but are getting headaches or migraine more than twice a week over a span of three months, schedule an appointment to speak with a doctor.

If you typically experience migraine, you know what to expect from your body when you have one. If your migraine symptoms last for more than 7 hours, or if you experience symptoms that aren’t typical for your migraine, call a doctor.

While more research is needed to understand exactly how heat is connected to headaches and migraine, we do know that dehydration, mineral loss, sun glare, and heat exhaustion can all cause headaches and migraine.

Be aware of the way that the higher temperatures can affect your body, and try to plan accordingly to prevent heat-induced headaches.

If you experience a headache in addition to symptoms of heat exhaustion, seek emergency medical care.