Your friend is a Type II diabetic since 4 years.
From the history iI assume that his blood sugars are not under control.
may be due to Hypoglycemia
. So his blood sugars may be fluctuating. He should be advised to regularly monitor and control his blood sugars.
Active physical life and regular exercise.
Frequent and small to prevent hypoglycemia.
Low temperature may be associated with hypoglycemia.