Margarita there can be lots of warning signs of a hypo, or none at all! I have to say that I have never seen any visible signs in my son, even when he has tested at below 2 mmol He has only actually come to grief through a hypo once, unfortunately when he was in Bulgaria and I was at home This link will give you some info on hypos http://www.diabetes.org.uk/Guide-to-diabetes/Complications/Short_term_complications/Hypoglycaemia/ Lucozade is the best and quickest acting treatment, provided the 'sufferer' is conscious and co-operative. Despite what you might hear, chocolate is NOT the best treatment as the fat in it slows down the absorption of the sugar. However, it would be better than nothing if something more suitable was not immediately available. Hope this helps.