Summer – Sun – Headaches: Can heat really give you a headache?

Summer – Sun – Headaches: Can heat really give you a headache? 

People who suffer from tension-type headaches or migraines often find that their symptoms worsen during the summer months. As temperatures rise, so does the fear of the next attack. Heat is believed to be a major trigger for the two most common types of headache disorder. But what does the science say? Is there actual proof of a connection? And what steps can you take to help prevent attacks?

Heat and headaches: an under-researched area

A quick comparison shows that far fewer studies have been devoted to the link between headaches and the weather than to other headache causes. Clearly, there’s a lot we don’t know about this topic. This article looks at the ways researchers are trying to shed more light on the issue.

A tentative research hypothesis: could temperature and air pressure really matter?

One current research theory – still tentatively worded – is that major changes in weather may contribute to the onset of headaches. Some research indicates that rapid shifts in atmospheric pressure may be a factor, as the studies presented in our article suggest.

A large-scale study involving over 7,000 participants at the Beth Israel Deaconess Medical Center in Boston also points to the influence of temperature and atmospheric pressure. Regarding the motivation behind the research, the lead investigator explained that weather factors are among the most frequently reported triggers for headaches, yet they remain some of the least studied and least well documented. With this study, they wanted to put these common beliefs (‘clinical folklore’) to the test and see if they have a basis in science.

One key finding of the study was a statistically significant correlation between rising ambient temperatures and the occurrence of headache or migraine attacks. Atmospheric pressure also emerged as an important factor: the acute risk of a headache episode increased significantly when atmospheric pressure was lower than usual in the 24 to 72 hours leading up to the onset of symptoms – in other words, during periods of low-pressure weather. This effect was especially pronounced in individuals affected by tension-type headaches.

What about air pollution?

Studies conducted in emergency departments at clinical centers across several major Canadian cities (Ottawa, Calgary, Vancouver, and Edmonton) examined air pollution as a potential factor in the development of headaches. Among female patients, researchers found a strong correlation between migraine attacks and sulfur dioxide (SO₂) levels in warmer months, as well as fine particulate matter levels during the colder season. Men, by contrast, were particularly sensitive to nitrogen dioxide (NO₂) exposure in the summer. This matters because hot weather – especially in densely populated urban areas – is often accompanied by a sharp rise in levels of air pollution.

Other studies have shown that periods of extreme heat bring additional challenges, particularly through the formation of so-called ‘heat islands’. These occur when air masses become stagnant in enclosed urban spaces, allowing solar radiation to heat the trapped air to very high temperatures. According to a recent report by a Dutch research team, headache attacks are observed with unusual frequency under such extreme conditions.

The day-night hormone: melatonin

Researchers are also looking into the role of melatonin in the development of headaches. Melatonin is a hormone produced in the brain’s pineal gland. It essentially acts as the body’s internal clock, by controlling our sleep-wake cycle and helping to coordinate biological processes so that they occur at the correct time of day or night.

A study conducted by a Norwegian research team found that, unlike the general population, people with migraines experience a drop in melatonin levels in their blood when exposed to sunlight. At the same time, migraine sufferers have long been known to be especially sensitive to light – a phenomenon known as photosensitivity. For individuals with this predisposition, exposure to bright light can significantly increase the likelihood of a migraine attack, making this especially relevant during the summer months. Researchers suspect that a malfunction in the part of the brain that helps control the body’s internal clock may contribute to migraine-associated photosensitivity.

Can you protect yourself?

The number one rule during hot weather is to stay hydrated. While the general recommendation under normal conditions is to drink at least 1.5 liters of water per day, it’s essential to increase your fluid intake significantly when temperatures rise. There’s strong scientific evidence showing that dehydration is a key factor in triggering both headache and migraine attacks. Since sweating also leads to a loss of important minerals like sodium, potassium, and magnesium, drinking fluids helps replenish these vital stores. Mineral-rich waters can be particularly effective.

Anyone prone to migraines should avoid direct sun exposure, especially during the hottest part of the day. When outdoors, protecting your head is important – your eyes in particular. A lightweight hat can help keep your head cool. Sunglasses with proper UV protection are essential.

If using air conditioning at home or in the car during hot weather, you should be mindful of the settings. If the air conditioner is set too low, the sudden change between hot outdoor air and cool indoor air can cause a shock to the system. At peak heat, the difference can exceed 20°C (35°F), placing significant stress on the body.

In hot weather, what you eat matters too. You should opt for foods that are nutritious but easy to digest. Regular meals containing sufficient complex carbohydrates are especially important for migraine sufferers, as the brain needs a steady and reliable energy supply—even in the heat. Avoiding large fluctuations in blood sugar levels is key. Lighter, nutrient-rich meals tend to be well tolerated by most people prone to headaches.

When it comes to exercise, you should listen to your body. Intense exertion in high temperatures puts extra strain on the body and can even trigger migraine attacks in sensitive individuals. The golden rule during hot weather is: don’t push yourself too hard. Be aware of the additional strain on your body, and make sure you get the rest and relief you need.