My ds's were born and lived as toddlers in a hot climate. If you're bottle feeding at this stage you will be able to find compatible formula at local chemists, same goes for nappies, although expect to pay much more than the UK.
Have a small flask that you fill with water at the right temperature for the bottles and make up only when needed, oh and make sure that everything is throughly sterilized, germs breed quickly in those temperatures.
Look up any clinics before you travel so if there are upset stomachs you know where you are going - private clinics in Greece are excellent.
Have an umbrella for the pram, plenty of hats (if possible with he neck flaps) and high factor suncream but keep baby out of the sun when ever possible.
I always had plenty of extra bottles with sterilized water (before I feed them I would always give them water first) in and made sure that my ds's drank as much as I could get them to manage.
Keep the clothes to an absolute minimum, my ds's when indoors at home, just had a nappy on.
You will be absolutley fine, have a great time.