Extreme cold temperatures and wind chill can lead to
hypothermia. Due to the thin ozone layer it is essential that a
high protection sunscreen be worn, and the glare from the ice and
water necessitates the wearing of sunglasses. The crossing of rough
seas will require most passengers to take some form of seasickness
preventative medication. All passenger ships have an onboard
doctor, but health insurance is imperative and must include
emergency evacuation, which can be exorbitantly expensive.