Hot sticky weather can be a pain for anyone, but now it’s clear that migraine suffers may be especially at the mercy of the thermometer.

According to recent study findings from Harvard that appear in the journal Neurology, when the outside temperature is above normal, migraine sufferers make more emergency room visits.

Researchers analyzed data from more than seven-thousand individuals who were treated for migraine headaches in the emergency room at one hospital between 2000 and 2007. With dates and times in hand, they compared that information with levels of temperature, barometric pressure, humidity and air pollution reported back then.

The researchers found a definite correlation, noting that the number of emergency visits for the severe headaches rose by an average of seven-and-a-half percent within twenty-four hours if the temperature outside rose by nine degrees above the typical temperature for that given day. They also noted there were more visits when the barometric pressure dropped.

Hotter temperatures, such as those in the summer, did not by themselves make the difference. But temperatures significantly above the average for a particular time led to more hospital visits, meaning even during the winter, warmer temperatures could trigger episodes for migraine suffers.

Experts say the findings don’t necessarily prove that temperature changes cause migraines, but that such fluctuations can be a trigger. Like chocolate, red wine and lack of sleep, an extra warm day just might bring on that headache episode.