It is a tropical country, mosquitos are always a threat but if you're staying in populated areas such as Phuket, the risk is lowered unless you will do a lot of trekking and hiking in forests and jungles.
It may be useful for you to know that treatment for Dengue is uncomplicated and simple in first world countries. First signs of dengue fever is dehydration and may be accompanied by one or more of the following: tachycardia; hypotension; an unusual rash; decrease urine output; and cool skin despite the weather.
It is important to stay hydrated in a tropical country especially if you are not from one - it may be hard for you to tell. By the time you feel thirsty with a dry mouth, you are already dehydrated.
People who are susceptible are those who are malnourished and who are otherwise immunosuppressed.
The only way to avoid it is to not be bitten. So, do as you normally would, use insect repellent, mosquito coils while you sleep and wear long sleeves and pants where you can.
Eat well, sleep well and enjoy your holiday! about 6 years ago