Krishnan Bhaskaran and colleagues from London School of Hygiene and Tropical Medicine have found that a drop in the average temperature outside is linked to higher risk of people having heart attacks, the 'British Medical Journal' reported.
In fact, each 1°C reduction in temperature on a single day is associated with around 200 extra heart attacks in UK.
The study was conducted on 84,010 patients who were with heart attack in 2003-2006. The results were adjusted according to risk factors like air pollution and rates of flu at the time.
The researchers discovered that 1C drop in temperature increases 2 per cent in the risk of heart attack.
Older people between the ages of 75 and 84 and with prior heart disease were more prone to the effects of temperature reductions than people taking aspirin.
"We found no increased risk of heart attacks during higher temperatures, possibly because the temperature in the UK is rarely very high in global terms. Our results suggest that even in the summer, the risk is increased by temperature reductions.
"From these studies you see an effect on blood pressure going up, the blood getting thicker and the heart working harder. Also the substances in the blood which help it to clot get a bit more concentrated," Bhaskaran said.
The researchers will go for further studies to help reduce in the risk of heart disease.