So maybe I shouldn't go winter camping in -40F weather anymore. No worries about running in hot weather, I can't run yet.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=144086&CultureCode=en
When temperatures are extremely high or low, there is a significant
increase in the number of deaths caused by heart failure or stroke. This
has been confirmed by epidemiological studies conducted by researchers
at the Helmholtz Zentrum München, who have now published their results
in the medical journal Heart.
Epidemiological studies have repeatedly shown that death rates rise
in association with extremely hot weather. The heat wave in Western
Europe in the summer of 2003, for example, resulted in about 22,000
extra deaths. A team of researchers led by Dr. Alex-andra Schneider at
the Institute of Epidemiology II at the Helmholtz Zentrum München
examined the impact of extreme temperatures on the number of deaths
caused by cardiovascular disease in three Bavarian cities and included
both high and low temperatures in the study.
“Our findings confirm the results of our previous studies, which
indicated that the elderly and people with pre-existing medical
conditions respond particularly sensitively to heat and cold,” says
Alexandra Schneider. “If you are aware of the effects of air
temperature on health, you can identify population subgroups who are
particularly at risk and take preventive action.”
The elderly are particularly at risk
Dr. Susanne Breitner, Dr.
Alexandra Schneider and Prof. Annette Peters evaluated almost 188,000
deaths due to cardiovascular disease between 1990 and 2006 in the cities
of Munich, Nuremberg, and Augsburg. They were able to demonstrate that
when temperatures rose from 20°C to 25°C or fell from -1°C to -8°C, the
number of deaths from cardiovascular disease increased significantly by
9.5% and 7.9%, respectively. While the effects of the heat lasted for
one or two days, the effects of cold weather lasted for up to two weeks.
Elderly people were most affected. The impact on death rates due to
heart failure, arrhythmia and stroke was particularly striking.
The mechanisms that cause these deaths, however, are not yet fully
understood.
Up to now it has been known that high temperatures, amongst
other things, can affect the blood-clotting mechanism (haemostasis) and
make the blood more viscous, thereby increasing the risk of thrombosis.
Furthermore, as decreasing temperatures have an impact on blood
pressure, it can be assumed that there is a link between cold
temperatures and the increase in cardiovascular events and stroke.
Preventative programs
“Our findings give an indication of the
diseases that are responsible for the observed link between air
temperature and death rates, and thus provide a partial explanation as
to why some people react more strongly to heat or cold than others and
are, therefore, exposed to a greater health risk on hot or cold days,”
says Alexandra Schneider. “These results are important in order to
develop or adapt preventive programs and codes of practice.”
The scientists plan to conduct further research into the mechanisms
that may be responsible for the health effects observed during cold and,
in particular, hot temperatures. They are also interested in possible
interactions with air pollutants, which are required in order to predict
the effects of climate change on the health of the population,
especially in cities and in major conurbations.
http://www.helmholtz-muenchen.de/en/news/press-releases/2014/press-release/article/24497/index.html
Full bibliographic informationBreitner
S. et al. (2014). Short-term effects of air temperature on
cause-specific cardiovascular mortality in Bavaria, Germany; Heart,
0:1–9. doi:10.1136/heartjnl-2014-305578