What should be done if a person shows signs of shock?

When a person shows signs of shock, elevating their legs and keeping them warm is a vital first aid measure. This action helps improve blood flow to vital organs, as raising the legs can facilitate venous return to the heart, which is critical when the body is experiencing shock. Keeping the individual warm can prevent hypothermia, as shock may lead to a drop in body temperature due to inadequate circulation.

The other choices do not effectively address the situation. Providing food and drink may pose a risk if the person is not fully conscious or may require medical intervention. Keeping an individual in an upright position can exacerbate the symptoms of shock by reducing blood flow to the heart and brain. Restricting movement is not necessarily a primary concern unless there are other injuries, and it does not directly combat the physiological changes occurring in shock. Therefore, elevating the legs while ensuring warmth is the most appropriate and beneficial response in this scenario.