 We explain how a heat stroke develops. This is Amelia. During the last few minutes she started feeling very sick. Her head throbs. She's dizzy and her heart is racing. The worst? She just fainted. What's wrong with her? Quickly an ambulance is called for. They check Amelia's core temperature which is above 40 degrees Celsius or 104 degrees Fahrenheit. Now they are sure Amelia is having a heat stroke. A heat stroke occurs when a person's core temperature is so high that their body is unable to cool down. This usually happens during a heat wave, but if you're not drinking enough non-alcoholic liquid and are doing very strenuous physical exercise, you're in danger too. Severe heat stroke is life-threatening and a medical emergency. To treat the heat stroke the ambulance team lowers Amelia's core temperature by putting her in a cool, shady rare-conditioned place and remove any unnecessary clothes. Then they apply ice packs to her neck, back, armpits and groin and fan air over her. When she's conscious, she must drink water. The risk of heat strokes increase when the temperature reaches 26 degrees Celsius or 79 degrees Fahrenheit. Other risk factors include age, dehydration, diabetes, mental illness, physical exercise, alcoholism and drug abuse, high blood pressure or just wearing tight and restrictive clothes. To prevent heat strokes stay aware of heat wave warnings and keep out of the sun during midday. Wear loose-fitting clothes and drink extra fluids. Take a cool shower or bath, or sprinkle cold water over your skin and clothing. Try to rearrange your day and work out during the morning or after sundown. To make it simple, stay as cool as possible.