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

Heat and headaches: still plenty to learn and discover

Compared to the number of scientific studies on other potential causes and contributing factors behind headaches, research into the effects of heat is still lagging behind. So far, this area has received relatively little attention from the scientific community. Nonetheless, there are some promising approaches aiming to shed light on the issue—several of which we’ll take a closer look at in this article.

Could temperature and air pressure really matter?

One of the more cautiously worded hypotheses in current research suggests that major changes in weather may contribute to the onset of headaches. In particular, rapid shifts in atmospheric pressure have been mentioned as a potential cause. Several studies seem to support this idea, at least.

A large-scale study involving over 7,000 participants at a medical center in Boston, USA, also pointed 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 demonstrable link between rising ambient temperatures and the occurrence of headache or migraine attacks. The study also indicated that the chances of a headache (a tension-type headache in particular) are higher if the air pressure in the 24 to 72 hours before the onset of symptoms is significantly lower than usual.

What about air pollution?

Studies in emergency departments at medical centers in several major Canadian cities (Ottawa, Calgary, Vancouver, and Edmonton) have explored air pollution as a possible contributing factor in the onset 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 air pollution levels – especially in densely populated urban areas – tend to spike alongside rising temperatures.

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 circulation is limited in urban zones, 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 question of whether – and how – the weather affects headache patterns has long been a topic of scientific interest. In case you missed it, here’s a link to a previous article we published on this subject.

The day-night hormone: melatonin

Another area of interest is the possible role of melatonin in headache development. 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 are often especially sensitive to light – a fact that has been known for some time. 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. The researchers also suspect that a malfunction in the brain region responsible for regulating the internal clock may play a role in this heightened sensitivity.

Can you protect yourself?

The single most important rule during hot weather is: 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.

As a general rule, people with migraines should avoid direct exposure to intense sunlight. When spending time outdoors, it’s important to protect the head – especially the eyes. 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 heatwaves: don’t push yourself too hard. Give your body the rest and relief it needs.