Stretch marks develop during pregnancy because of rapid and excessive weight gain in areas such as lower abdomen or thighs. As weight increases, collagen and elastin in dermal layer of skin, responsible for retaining shape and firmness, is stretched to point of breaking. The dermis is layer beneath epidermis, or visible layer of skin. The elastic fibres in dermis weaken with stretching and increased cortisone levels normally produced in last trimester. As these fibres separate and skin stretches, collagen is overproduced to form scar tissue which result in striations.

Hypothermia is a condition marked by an abnormally low internal body temperature. It develops when body heat is lost faster than it can be replaced. Normal muscular and cerebral functions become impaired and death can follow if it becomes worse. This takes place below 96º F and lower.

Signs of hypothermia include confusion or sleepiness; slurred speech or shallow breathing; weak pulse or low blood pressure; stiffness in arms or legs or poor control over body movements. Severe hypothermia can cause an irregular heartbeat, leading to heart failure and death.

Symptoms of Hypothermia

Shivering is typically first sign of hypothermia. It eventually becomes uncontrollable. However with severe hypothermia, shivering stops. One of key indicators that victim has moved from mild/moderate hypothermia to severe hypothermia is that he/she is no longer shivering.

Behavior changes like complaining, difficulty in speaking, and uncoordinated movements. Victims will struggle to perform simple tasks like walking a straight line or zipping up their coat. With severe hypothermia, behavior changes from erratic to apathetic to unresponsive. Uncharacteristic behavior like inappropriate excitement or lethargy, poor judgment, and poor decision making are common.

Cold, pale and blue-gray skin due to constricting blood vessels. May develop into a coma, with dilated pupils making it difficult to determine if victim is alive or dead.

How Heat is Lost from Body

Convection: Heat is carried away from body by currents of air or water. Wind chill is an example of convection.

Conduction: Transfer of heat between two contacting surfaces. Water conducts heat 25 times faster than air and steel is even faster than water. Generally conductive heat loss accounts for only about 2% of overall loss. However, with wet clothes loss is increased 5 times.

Evaporation: Heat loss when water is removed from body during sweating and respiration.

Radiation: The loss of radiated heat from a warm body to a surrounding colder environment. This is more significant on cold, cloudless nights. Factors important in radiant heat loss are surface area and temperature gradient.