Congratulations on your new baby!! I think you all will have a wonderful trip. I agree with other posters in that I thought the current recommendation for sunblock is 6+ months, so check with your pediatrician on that, but if you still can't use it, I'd definitely try to find some UV-blocking clothes. I somewhere read that there was some UV-blocking thing you could wash in with your clothes to make them more UV-blocking (if that makes sense... google sunblock clothes or something and it should come up), and I would definitely do a sunblocking hat (Target and BRU sell them in the summer, and I'm sure you can find them online or in warmer areas). Also, the sunblocking extra add-on thing for your stroller (BRU sells it with stroller accessories - maybe on clearance now possibly?). If you're using a carrier, some (like the Ergo) have a "sleeping hood" that would be good head protection for when your son is sleeping (we wore our 14 month old in it while at DL earlier this year and it was a HUGE blessing while we were there... and we could still go on rides with her in it!). In reality though, I think the easiest thing would be sunblock... the natural kinds are way less "chemicals" and really, I'd personally rather that my kid got a few chemicals for a few days (that we immediately wash off as soon as we get home or before long naps) than a sunburn. Hopefully his skin isn't too sensitive and can handle something. I hope you all have a wonderful trip!