When my kids were little, vacations were like an invitation for someone to become deathly ill while far away from home. We've had:
screaming high fevers after hours in a strange city where we called ahead to urgent care who said come on in then they closed before we could get there 15 minutes later,
the trip to Hawaii where 4 of us caught the flu on the plane and spent the week in bed,
the RV trip to the family reunion which was going great til right after dinner when my mother-in-law informed us that those bumps all over 3 of my kids weren't mosquito bites, they had chicken pox and had just exposed all of their cousins,
the camping trip where my kids started throwing up just 1 hour drive away from home with the stomach flu,
the RV trip where each of us came down with the stomach flu one by one on the drive home,
driving 14 hours to see my folks for Christmas, kids got sick after a couple of days so we turned around and drove home missing the big family party we'd looked forward to,
visiting friends in Arizona, we gave my 1 yo daughter a lick of peanut butter, she broke out all over in hives because we didn't know she is deathly allergic to peanuts and nuts, couldn't find a medical center open on that holiday weekend and ended up calling her pediatrician long distance to figure out what to do.
There's more, but I used to wonder why I even planned vacations with our history. It's gotten better, though. My youngest 2 are teenagers and it's been years since anyone has gotten sick on a trip.