#illnesses When you do intense exercise, your brain could run out of oxygen temporary. It could very severe. ## Symptom 1. yawning 2. your ear is stuck. Cannot hear outside voice. Hear your voice in the skull. 3. you feel dizzy 4. you feel vomit 5. your limb is cold and tremble 6. your noise and your lip is cold 7. your sight can black out ## How to Prevent? The earliest symptom is yawning, as soon as you start yawning, you should stop and wait for recover. ## How to Recover? 1. lay down on your back. Don't stand, don't sit. Lay down. 2. ask for help. 3. move to area with fresh air and breeze. don't let people walk too close because it can block the air. 4. breath deeply but slow. breath consistently. 5. keep talking. If you are helping someone, ask them repeat what you said. Just keep themselves or yourselves talking. 6. keep yourself conscious. 7. feel your noise and lip. Keep laying down until you don't feel cold anymore. 8. As you recover, you lib can feel even colder. It is because the blood and oxygen goes to the brain, just keep laying down until they are not cold. 9. when you feel better, try change to sit position and stand. Don't move and walk. Until you feel better, start walk **very** slowly, as slow as an old lady. Then after you feel like you fully recover, you can walk normally and thx people for help.