It might also ease your mind to know that the particular species which transmits Dengue is only active during daylight hours - thus you generally do not have to worry about contracting Dengue at night.
Even during the daylight hours, risks are highest during the early morning and during the evening hours. Thus, make sure that you use a product containing DEET especially during those times (such as during a sunset walk on the beach, for example.)
Further, please be aware that the concentration of DEET in a given product is NOT related to its effectiveness. It is a common misconception that you need higher concentrations in order to be better protected.
However, a product containing 5% DEET is EXACTLY as effective as one containing 30% DEET. The concentration of DEET simply affects HOW LONG the product can offer protection.
Thus, 100% DEET will provide protection for 12 hours.
25%-30% protects for up to eight hours.
15% protects for up to six hours.
5%-10% gives you protection for 2 to 4 hours.