Brunei

Brunei's preparation is behavioral, not pharmaceutical. There is no malaria, but dengue circulates year-round and has no prophylaxis — DEET 30%+ and permethrin-treated clothing are the medicine, doubly so in Ulu Temburong's rainforest. The other half of the briefing is legal: Syariah law applies to everyone, so alcohol stays in your hotel room within duty-free limits, public eating during Ramadan daytime is an offense for all, dress modestly at mosques, and understand that drug trafficking carries a mandatory death penalty. None of this is theoretical; it is simply how the country runs, and travelers who know the rules find one of the safest destinations in Southeast Asia.

The thing most travelers don't realize is how good the medicine is. RIPAS Hospital — 1,260 beds, UK Royal College accreditation, Australian-trained staff — is genuinely capable acute care, and Gleneagles JPMC runs the country's tertiary cardiac center. The geographic caveat is Temburong: the district is pristine, separated from the capital, and thirty to sixty minutes by boat from any hospital, so tell your accommodation your itinerary before heading into the canopy. Complex cases fly to Singapore in ninety minutes. Before any of it: the E-Arrival Card and the Bruhealth health declaration are mandatory pre-arrival steps — handle both the week you buy the ticket. Hepatitis A earns its place here; the night markets at Gadong are worth protecting.