Yesterday we're driving 7 hours to our vacation destination. We take two cars because it's an extended vacation. 5:30pm - BG is 160 so wife gives 0.5u Now we switch cars and I'm with the boys 6:30pm - BG is 210 so I give additional 0.8u (we use CF of 90) She had been running him at +30% temp basal so I up it to 60% because it seemed the +30 was not high enough and during previous drives we'd run him at +50 to +60%. The back story: we recently had what I judged to be a horrible A1C, he'd been above 200 all day two days ago, and I really struggled to get him down. So with the inactivity for 7 hours, the recent stubborn highs, I thought to myself, "I am not going to let him creep into the mid to high 200s again", hence the additional correction and increased basal rate. We are close to our destination and stop for pizza. 8:40pm - BG 101 (no arrow) He eats a 10 inch thin crust pizza. Wife and I estimate 80 carbs and bolus 30% up front and extend 70% over 1.5 hours. 9:25 pm - CGM reads 80, finger stick reads 78 flat arrow I cancel the extended bolus. 9:35 pm - CGM reads 72 flat arrow, but he feels low and I give 10g of juice. 9:45 pm - CGM bumps up to 74 9:47pm - "DAD, I FEEL REALLY LOW" 9:48pm - Finger stick - 34 DEFCON 1 in our house. Juice and tabs. Son is very shaky. 10:02pm - BG 82 10:18pm - BG 99 11:00pm - BG 249 I clearly gave him too much insulin. The increased basal and correction hit him fast and furious when I thought I'd again me met with more resistance. I always thought his first sub 40 number would be due to extreme exercise, but no, it happened right under my nose with him in the car with me. 11:05pm - Son says to me in bed, "I hate my life. I hate Diabetes". 11:06pm - Dad feels good. Real good.