"Cold weather puts an extra strain on the heart, " the CDC said, also noting that overexertion can become even more dangerous to those with heart conditions in the Arctic cold.

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When people first immerse themselves in such frigid water, their bodies go into "cold shock, " and they start gasping for air, which puts a strain on the heart.

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Rather than putting extra strain on services vital for real emergencies at this busy time of year people with cold and flu symptoms should use available medication and if worried visit a pharmacist for expert advice.

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