There is a reason why emperor scorpions are the most popular scorpions in the pet trade. Emperors are the most friendly and docile species of scorpions that exists. 

Very rarely will you ever get the chance to see an emperor sting.  Even when the scorpions catch their pray, they almost always use their power claws to kill it.  Even if I make my scorpions mad, as when cleaning their cage, they are very hesitant to use their stinger. Emperors would rather run away and hide than stay and fight. If indeed you do make them mad, they are more likely to pinch you than sting you.  Their claws can hurt worse than the stinger, as the claws can draw blood if they pinch you; they are extremely powerful.

If you do end up getting stung you don’t have much to worry about. Emperors have very mild venom, and it has been compared to a wasp in terms of pain and toxicity.  However, you still need to be cautious when handling them or putting your hand in the cage. Some people are allergic to the venom (like people and bees)  and it could cause extreme illness or possible death. Handling is not advised.