Pack a complete change of clothes for each child. Shirt, pants, underwear, socks, shoes if you can afford them.
Saturday I took my kids out, and my youngest decided to pee her pants. Unfortunately their go bags were in my car and I was driving my mothers vehicle instead. We weren't going too far (20-30miniutes away) so I decided to forgo swapping the bags around. My mistake. We were forced to leave immediately because I had to strip everything off from the waist down of my little one as it was soaked. So endith the day.
I occurs to me that kids of any age could end up in a situation where clothes have to be changed. Falling in mud, getting in a fight, spill food at a party, potty accident, stepping in something nasty, whatever. And most of the entire outfit may need to be changed...You know, thinking about this while I write suggests that the same may be true for you and I as well.