Here after are some healthy advice gathered on different recommended websites as well as an informative list of medical institution available of the French Embassy website. https://kh.ambafrance.org/Fiche-medicale .

Vaccinations. Although no vaccinations are officially required for entry to Cambodia, they are highly encouraged. Visitors are advised to check with their doctor or a travel immunization clinic regarding protection against malaria, typhoid, tetanus, hepatitis A and B. Any essential medications should be brought with you as there is no guarantee they will be available in Cambodia.

Water. In Cambodia, you are advised to drink lots of water. However never drink tap water. Bottled water is available everywhere, including in the street where you can spot the sellers with their orange cooler.

Mosquito bites. Use an insect repellent against mosquitoes. It is the only way to be sure of protection against mosquito borne diseases.

Heat. Since Cambodia has a hot and humid tropical climate, casual and light-weight clothing is best. Clothing made from natural fibers is the best option. A jacket might be needed on cool winter evenings or in hotels and restaurants using excessive air-conditioning. A hat and high-factor sun block is advisable as protection against the hot sun when sightseeing.

Sources:

http://www.tourismcambodia.com/tripplanner/essential-information/health-and-advice.htm

https://travel.state.gov/content/passports/en/country/cambodia.html