Can Hot Weather Give You a Heat Headache?

Headache and migraine triggers differ from person to person, but headaches can be a symptom of heat-related disorders, such as heat exhaustion. Although heat itself does not cause headaches, its effects on the body can.

A heat-induced headache or migraine can feel like dull pain on both sides of the head and may get worse with activity. It can happen for several reasons, including dehydration, excessive sun exposure, or physical exertion in the heat.

This article explains how environmental conditions and lifestyle factors during hot weather can cause headaches, the symptoms of heat-induced headaches, and how you can treat a headache brought on by heat.

How Hot Weather Causes Headaches

There are a few heat-related factors in your body and environment that can bring on a headache.

Dehydration

Many people look forward to the warmer summer months because they can do more activities and sports outside. 

However, heat also has some downsides. Not drinking enough fluids when you’re outside in hot weather can leave you with a dehydration headache.

When you are dehydrated, you have less fluid in your body tissues and brain. When this happens, your brain tissues shrink and pull away from the skull, causing nerve pain. Drinking fluids will help get the tissue fluids back to a normal level and is often enough to fix the headache, too. 

Sun Exposure

In some cases, sun exposure can trigger a headache or migraine.

Photophobia is when a person has abnormal discomfort and sensitivity to light. It is a neurological symptom that happens because of problems with the transmission of information between the eye and brain.

The part of the eye that transmits light to the brain is different than the part of the eye that helps you see. For this reason, even a blind person can get a photophobia-induced headache.

Barometric Pressure

Barometric pressure is the air pressure level in the atmosphere. Summertime thunderstorms are a common cause of barometric pressure changes. Research has shown that even small decreases in atmospheric pressure can induce a migraine or headache.

Hormonal Changes

Hot flashes are common during perimenopause. They are caused by changes in estrogen levels.

Estrogen works with a part of the brain involved in regulating body temperature. Low estrogen levels can increase the body's temperature and cause common menopause symptoms like hot flashes and night sweats.

Physical Activity

Headaches can be caused by physical activity when the weather is too hot, leading to heat exhaustion.

Heat exhaustion is when the body gets too hot and cannot cool itself down. This happens more commonly during warm and hot summer months, especially when it’s also humid.

Other symptoms of heat exhaustion include:

• Dehydration
• Dizziness
• Muscle cramps
• Nausea and vomiting
• Heatstroke (which can be life-threatening)

Heat Headache Symptoms

Headache symptoms may include:

• Mild to moderate pain on both sides of the head
• Head pain that gets worse with activity
• Consistent pain that is dull but not throbbing

If your heat headache symptoms come along with confusion, slurred speech, weakness, or numbness, call 911.

Heat Exhaustion Symptoms

Symptoms of heat exhaustion include:

• Heavy sweating
• Cold, clammy skin
• Tiredness
• Weakness
• Headache
• Fainting
• Dizziness
• Nausea and vomiting

If you start to experience heat exhaustion symptoms:

• Sip water
• Move to a cooler place
• Take a cool bath or place cool compresses on your body
• Take off or loosen clothing
  

Treatment for Heat Headaches

One way to help prevent heat headaches is to drink plenty of water and take breaks from activity during hot weather.

Once you feel a heat headache coming on, take measures to keep it from getting worse like:

• Finding a place to cool down and rest
• Drinking water for hydration
• Trying over-the-counter (OTC) pain medications (e.g., ibuprofen or acetaminophen)
  

When to Seek Medical Attention

If your symptoms do not improve after about an hour of rest and fluids, call your provider. Call 911 or go to the nearest emergency room if:

• Your symptoms last an hour or longer
• You develop even more severe headache pain
• You are vomiting
• Your symptoms continue to worsen
• You experience a change in neurological function
• You become confused or weak
  

Coping With Excessive Heat

Sweltering weather can be a challenge and you can’t always avoid being in extreme temperatures. If you can't beat the heat, here are a few ways you can stay safe:

• Keep a water bottle with you and drink plenty of fluids
• Check the forecast to prepare for hot weather
• Keep headache medicine on hand
• Wear lightweight and loose-fitting clothes
• Stay with family or friends while in high heat in case someone needs help
• Wear and reapply sunscreen regularly
• Bring a sun umbrella
• Sit in a pool or go swimming to cool off
• Change your schedule to avoid the heat (if possible)
  

Summary

Headaches can be a symptom of heat-related disorders, such as heat exhaustion. Although heat itself does not cause headaches, it can put you in situations that lead to headaches, such as dehydration. 

Hot weather headaches can also be caused by sun exposure, barometric pressure, and physical activity.

If you have a heat headache, finding a place to cool down and rest, as well as drinking water for hydration, can help keep it from getting worse. You can also take OTC pain medications to relieve your head pain.

If these measures are not helping, you may need to call your provider for treatment. If you have extreme headache pain or other concerning symptoms call 911 or go to the ER right away.