Well I dont carry the insulin vial (seems a waste, as I so rarely have to use it, to have to throw it out after 4 weeks), but I carry a spare set at all times (like @tim – I have an emergency kit in a purse with glucose etc that moves from one bag to another). And like @tim, was quite glad a couple of weeks ago, when a set didnt ‘take’. After 4 hours, BG 13.0 (I obviously climb much slower than @stephen !). Got out the spare set, stuck it in, moved over tubing. No probs. Problem came when I took the old one out and the reason for it not taking became obvious, as copious amounts of blood spurted everywhere (must have stuck it in too near artery/capilliary/whatever). Luckily I’d gone into the Ladies to change it, or there would be stains all over the carpet…