It depends how much sugar. I have type 1, and if I had 20 grams on accident, it could ruin my levels for half a day but not the end of the world. If I had 45 grams (a can of soda) or more on accident I’d probably just go to the hospital at that point. Or at least I’d be scared. Once blood sugar levels get too high it’s rough to control and you’re in a somewhat fragile state. And also you start to feel like shit the longer it goes on (dka.)

I guess I’m saying is usually no it won’t kill you but especially for type 1 people it’d probably make for a somewhat traumatic experience.