19. Your feet are going to swell
Maybe it doesn’t happen to you. Maybe it doesn’t happen to everybody and maybe it depends on where you go and the time of year but, me? My feet swell. Pretty bad, usually.
The problem is we sweat. A lot. If I’m wearing my small backpack (which I cart around my camera and lenses in; I may reevaluate my camera options for a future trip), in Ho Chi Minh City in south Vietnam, pretty much as soon as I walk outside, I start sweating profusely. Within 20 minutes, the back of my shirt (COTTON IS EVIL) is soaked through. Completely. Wring it out and there will be lots of water on the ground wet. Hard to get dry again wet.
That’s a lot of water. Moreover, that’s a lot of salt water.
To the north in Hanoi, in December, it’s not nearly as bad (a balmy 80 degrees) but it’s still a problem.
What to do about it? Drink lots of water or sports drinks (buy the 1.5 litter bottles) and eat lots of salty foods/snack foods. You need to replenish the salt your body is losing through sweat. When your body loses that salt, and it doesn’t get replaced, your feet swell.
Sounds easy, right? Well, it doesn’t always work at that way, so be prepared if they do swell, and don’t be too horrified.