My puppy is due for surgery this week. My vet told me to give him no food and water the day before, however it's very hot here right now. I'm worried about him becoming dehydrated. Any advice?

I would imagine your vet will have meant no food or water from about 9 o'clock in the evening the day before surgery, certainly not all day, so all should be fine.  As you suspect, it would be dangerous to withhold water all day in any circumstances, never mind when it's hot.

May be worth a quick phone call to your vet just to make sure what time he needs this to start.

M.

Thank you for your help. I forgot to mention that I'm in South Korea and the English spoken here is very limited. After care was also questionable. Would I need a carrier to bring him home? Was going to have a friend pick us up. What about excercise after? I live on a fifth floor apartment. Should I carry him upstairs after the surgery?
Thanks !
Sb