The most common health issues reported in Koh Tao are:
Heatstroke / Sunstroke
Make sure to drink plenty of water and ration your sun exposure every day. If you are drinking alcohol or smoking then drink even more water. There are rehydration salts sold all over the island to mix with your water for good absorption of salts.
The moist and humid climate of Koh Tao along with ocean water makes it difficult for wounds to heal. If you have an opened wound from an accident or mosquito bite make sure to clean it properly, use antibiotic /antibacterial ointment and stay out of the water. Clinics around Koh Tao can help you dress and keep your wounds clean.
Women should be aware that the combination of sitting in wet bathing suits and dehydration can bring on this uncomfortable condition. Bring dry change of clothes when diving and laying around the pool. Also bring along some probiotics in case antibiotics will be the only option.
Thai food may contain a lot of chilli and coconut milk which can be different to digest if not used to it. Take it easy with the spice and one should have no problem. It is a good idea to brush your teeth with the local tap water as a way to build immunity, but always drink mineral water as a beverage. Fruits and vegetables are usually fresh and clean and so is the ice, just remember to ease in and drink plenty of fluids.
Dengue fever is a virus transmitted through daytime mosquitos with no available vaccine. The symptoms are usually a persisting high fever, rash, muscle ache and a deep pain behind the eyes. If you experience these symptoms head to the nearest clinic for a blood test to confirm the diagnosis. Dengue can be sever so it is important to use mosquito repellent with deet when going out.
The following are routine vaccinations recommended when traveling to Thailand. Please note that certain vaccinations are only necessary if traveling throughout Thailand and South East Asia and may not be necessary for a trip to Koh Tao. Consultation with a family doctor or travel health clinic prior to departure is highly recommended in order to get the most accurate information about vaccinations. Also be aware that some vaccinations must be administered months before they can become effective. Make sure to visit your doctor well in advance of your planned travel date.
Make sure that you are up-to-date with routine shots such as, measles/mumps/rubella (MMR) vaccine, diptheria/pertussis/tetanus (DPT) vaccine, polio virus vaccine, etc.
Hepatitis A or (IG)
This vaccine is recommended for all travelers to South East Asia where exposure through food and water may occur and may be common.
This vaccine is recommended for travelers to South East Asia who may have exposure to blood, body fluids, have sexual contact with local population, or be exposed through medical treatment (e.g. via an accident or open wound).
The Typhoid vaccine is recommended for those traveling to rural areas and smaller cities in South East Asia. Typhoid contamination occurs through food and water. There are no known cases of Typhoid on Koh Tao.
This vaccine is recommended for travelers heading to rural or farming areas mostly in the north of Thailand. There are no known risks of Japanese Encephalitis in Koh Tao. This vaccine usually requires one month period before it is effective. Tip! If time permits, receiving the vaccine at a Bangkok hospital will be a fraction of the cost.
There are no known reported cases of Malaria on Koh Tao. There are also no vaccines for Malaria however anti-malaria drugs are available. If you are planning on heading to forested and rural areas near the Myanmar border, Laos, or Cambodia talk to your local travel clinic for the most effective prophylactic for you.
There are cases of Dengue Fever on Koh Tao however there is no available vaccine. Make sure to use mosquitto repellent with deet and mosquito nets (or air conditioning) when sleeping to avoid those unwanted bites.