The study revealed that a drop of just 1 degree Celsius, or 1.8 degrees Fahrenheit, translated into a 2-percent rise in the number of heart attacks in the following weeks.
The study of 84,010 hospital admissions for heart attack found that people aged 75 to 84 and people with a history of heart disease seemed to be most vulnerable to the effects of cold weather.
People who had been taking aspirin long-term were less vulnerable to temperature drops.
Researchers say more study is needed to better define which individuals are most vulnerable to temperature drops and to determine whether adaptive measures, such as adding clothing or turning up the thermostat, might help reduce events.
The study is published online in the journal /*British Medical Journal*/.