We are all different. I'm fine at 3.5, but not everyone is. 3.5 - 5.5 is a quoted normal for non-diabetics
As a rule-of-thumb, "4 is the floor". If you start to feel shaky or not quite right, check your BGs. If you're low, chew a couple of glucose tabs and test again in 15 minutes. If still too low, have another. If you're already feeling better, then have a digestive biscuit or a couple of oatcakes to keep you going until you can have "proper" food.
I have 2 test kits, one at home, one in my handbag. I also have glucose tabs (available from all chemists) in each kit, in my bag, in the car and at home. I think I've only had to use them once, but better safe than sorry. I have a Type 2 friend who has no hypo awareness and is forever collapsing in public and getting the paramedics out. She's been told by her HCP that testing is unnecessary for Type 2s :roll:
Viv 8)