It's wise to purchase travel insurance. There are many insurance companies that offer international medical/travel insurance as well as trip cancellation insurance.
Here are some examples:
Phone: (800)451-9699
Email: info@insurancebrokersusa.com
Website: www.insurancebrokersusa.com
Phone: (800)335-0611
Website: www.sevencorners.com
Phone: (407)830-0259
Email: john@insurance-network.com
Website: www.insurance-network.com