Fatal heart attacks spike in the weeks following Christmas, and researchers now think they've unwrapped just why this is.
Too much booze, stress and fatty food all play a part, as does holidaying far away from medical care, suggest researchers from the University of Melbourne.
Previous research in the US had found a link between the new year period and cardiac arrests, but it wasn't clear if the cold northern hemisphere winter was to blame.
Looking at 25 years of New Zealand data, researchers found the same spike - in the middle of the southern hemisphere summer.
Cardiac arrests jump 4.2 percent between Christmas Day and January 7, compared to the surrounding weeks, and the average age of heart attack victims drops a year, from 77 to 76.
The study's lead author, Josh Knight, says this proves the holiday - with its "more difficult access to hospitals... stress, an excess of alcohol and a fatty diet" - is what kills people, not the weather.
"The Christmas holiday period is a common time for travel within New Zealand, with people frequently holidaying away from their main medical facilities," he says.
"This could contribute to delays in both seeking treatment, due to a lack of familiarity with nearby medical facilities, and due to geographic isolation from appropriate medical care in emergency situations."
He also suggests many sick and elderly, determined to see their family one last time, let go once they've made it past Christmas Day.
"The ability of individuals to modify their date of death based on dates of significance has been both confirmed and refuted in other studies, however it remains a possible explanation for this holiday effect."
The study was published this week in the Journal of the American Heart Association.