Hi Thank you for asking HCM I have gone through your query.When diabetes goes above 300-400 diabetic ketoacidosis can come.In such case also the symptoms starts with stomach pain.High blood sugar can cause an urinary infection which gives stomach pain high temperature and shivering.He will be needing antibiotics and insulin therapy at least for some days till his sugar normalizes.So it is better to approach ER in this case.In case of sugar goes above 300-400 and ketoacidosis with out treatment it is fatal for patient.Hope this may help you. Let me know if you have any further query.