If you are caught in your vehicle during a hailstorm you should immediatly slow down and pull over when safe to do so. Locate and switch on your hazzard lights and stay inside the vehicle. Hail falls fast and at high speeds and can be large in size and speeding up will only cause more damage and or injury. Hail can break windscreens and windows, so if possible lie down, and keep your back to the windows. If you have a blanket or any other form of protection, cover yourself with it to prevent possible debris from hitting you and causing injury.