We learned that exposure to extreme temperatures, especially heat, can trigger a fatal heart attack in some people.

According to research published in the journal Circulation: Cardiovascular Quality and Outcomes, exposure to extreme temperatures can cause sudden changes in several important cardiovascular vital signs, including blood pressure, blood thickness, cholesterol and heart rate.  

While none of these spikes are necessarily fatal in and of themselves, they can become so for someone who is obese.   As the obesity rate rises across the country, extreme temperatures – especially very high heat and humidity – will become more deadly for more people.