Thailand attracts 30M+ tourists yearly and the wellness/training industry is mature. Major safety considerations:
Muay Thai camps — very safe at established gyms. You won't be forced into hard sparring as a beginner. Beginners typically get 2–4 weeks of light technique work before any contact training. Stick to camps with English-speaking staff and visible insurance signage.
Yoga retreats — extremely safe. Main risk is improper guidance for beginners. Look for certified teachers (RYT-200/500 from Yoga Alliance) and avoid unverified "spiritual" retreats with no online reviews.
Diving — generally very safe at PADI/SSI 5-Star centers. Verify dive shop certification before booking. Avoid super-cheap Koh Tao "fun dive" operators with no certification on display — fatalities have occurred at unregulated shops.
Spa / massage — virtually risk-free, but for therapeutic massage check that the therapist has TAT (Tourism Authority of Thailand) registration if you want medical-grade work.
Bigger actual risks: - Scooter/motorbike accidents — leading cause of tourist injury. Avoid renting bikes if you're not experienced. - Tuk-tuk overcharging — agree on price first or use Grab/Bolt. - Unlicensed dive shops or "free trial" muay thai gyms with hidden fees.
Travel insurance is strongly recommended (~$50–$100 for a 2-week trip).