An overdose of Humalog can be very dangerous, even fatal. A Humalog overdose may result from an error in administering or calculating your dose, from failing to eat after taking a dose, or from exercising more than usual after taking a dose. In these cases, hypoglycemia, or low blood sugar, can occur. Hypoglycemia can be a life-threatening condition if not treated right away. If you experience the symptoms of hypoglycemia, your should follow your doctor's instructions, which may include taking glucose or injecting glucagon to raise blood sugar levels.
In addition, you should wear an identification bracelet so others can tell you are diabetic in case you are unable to take action yourself. Your family and friends should know what to do in case of emergency.