My youngest daughter was 18 months when we first took her away to Cyprus (as was my eldest - same age, same hotel). The day before she looked a bit off colour, took her to the doctors but the useless receptionist (my niece!!) overbooked and we didn't get seen. She seemed ok the next day, it was really cold (though it was june or july), so she was covered in coats and things (it was really really cold...ok we went in the middle of the night but can remember the taxi driver was late picking us up because he had to de-ice the car). Got there, unpacked, and started to put the swimsuit....and she is virtually covered in chickenpox Ended up going to the hospital, driven by a crazy female taxi driver (making my eldest throw up with her driving), and spending hours there getting something for it. She ended up having to stay in the shade or in the room all day as she couldn't wear suncream...we spent several days going back and forward to the hospital getting permission to fly. Eventually we got it...hubby was worried as he would've been the one staying with her, as eldest was on my passport and the insurance company would only pay for two people to stay.
Luckily we got back and her chickenpox healed quicker than normal, maybe because of the sun.