Staying healthy while traveling · Cambodia

Hi there... I’m traveling with a friend for a month in November. We booked our round-trip tickets from Paris to Phnom Penh, and yes, I know—it was a mistake. We should’ve flown out of Laos, but here we are. But is it doable to backpack through both countries in a relaxed way? I’ve seen that the transport takes a while... Thanks so much for your replies.