What are the factors to consider when planning to travel?

Other countries don't necessarily pay for healthcare in the same way and in any case, as a foreigner they will probably charge you for it if you fall ill while there. So buy travel insurance and that includes health cover. It doesn't cost much for a short trip. If you are British and planning to travel within the EU, get a European Health Insurance Card. This is free and stops you getting overcharged. Probably you still have to pay something, but not as much and you can claim that back on insurance. The USA has the most expensive healthcare in the world and without insurance, having an accident there can make you bankrupt.

To go to somewhere more exotic, get your jabs. Get advice from your doctor or from online, preferably a government web site, as to what vaccinations are advisable. I'm British and when going to Mexico for 2 weeks I was advised to get, and got, vaccinations for hepatitis A, typhoid, diphtheria, tetanus and polio. Some countries, particularly in Africa, require an actual certificate of vaccination against yellow fever. Where malaria is common, you will be advised to start a course of treatment before you even go and keep it up while you're there. There is no vaccination against it but a course of tablets is effective.

Time zones... 2 or 3 hours difference is not a problem but for any more, plan to deal with it. Flying across the Atlantic is 5-8 hours difference and that's not too bad going east to west - it just feels like an enforced very late night - but coming the other way is awful. You arrive at a later time than your body thinks it is and you just want sleep in a country where it's already the following day. Going west to east, don't plan anything for the first day as you won't feel like it.

Does the country require you to get a visa first? Google the embassy of that country in your country and it should tell you. If you need a visa and don't have one, you won't be let in. Russia is a fun one... all visitors there need a visa, and the visa application has to be supported by your hotel booking written in Russian. My mother wanted to see Moscow and her first visa application got refused because she sent the wrong piece of paper. OMG, she's English and she doesn't read Russian (it uses a totally different alphabet) so it's no surprise she got it wrong, but fortunately there was enough time to try again and she got her holiday.

In general, research first where you want to go. Good guidebooks always contain an advice section at the front and there is nothing better than buying one or borrowing one from the public library.

Healthcare has a lot to do with awareness of your self, others and destination.
Self: personal safety, hygiene, nutrition
Others: keeping out of 'dodgey' areas, always keep handbags close, hand luggage locked
Destination: how do you get safely from the airport, temperature, humidity, language, expected costs