A new study published in the medical journal Heart has revealed that if there are extremely high or low temperatures in the environment  it can cause heart failures or brain strokes.

A team of researchers led by Dr. Alexandra Schneider at the Institute of Epidemiology II at the Helmholtz Zentrum Munchen have confirmed that high temperatures can affect the blood-clotting mechanism and make the blood more viscous, thereby increasing the risk of thrombosis, while decreasing temperatures have an impact on blood pressure, thus increasing risk of death in both cases.
The study has also shown that elderly and people with pre-existing medical conditions respond particularly sensitively to heat and cold. The findings could also  help in identifying population subgroups who are particularly at risk and take preventive action. The findings show a direct link between air temperature and death rates which causes these deaths and when these people are subjected to extreme conditions are  at greater health risk and it is vital that preventive measures be taken to avoid these deaths.
 Source:Heart.