You risk hypothermia when you seek to cool down by leaving a hot environment for a cool one. Eat high energy food, such as nuts and raisins. Avoid alcohol, coffee, tea and tobacco. They can cause heat loss. Sudden heart attacks increase during a cold snap.
Cold air can cause blood pressure to go up, especially when skin is exposed.
Another danger is hypothermia, sometimes called exposure. Shivering is a serious warning sign to seek a warmer, sheltered place. If you suspect hypothermia, take measures to prevent further heat loss and get medical help as quickly as possible. Continue the warming efforts even if there is little or no pulse or heartbeat. Severe hypothermia can be mistaken for death.