ouch F3000 fan..sounds nasty.
Ive had one or two shunts that were pretty nasty at around 65 mph (which is top speed for my kart) but thankfully no injuries.
both happened on a straight and involved someone eles mistake and i had nowhere to go and slammed into them.
the second one I actually got airborne after hitting a sandtrap sideways and slammed into a tyre barrier while in the air..unfortunately my foot had slipped under the brake pedal with all the jolting around and got squashed between the tyre wall and the brake pedal ...gave mea bit of pain but nothing was broken
just genral karting can make you very sore..bruises are common place especially around the lower back area ..but good padding helps that out.