Fragrances are designed to last about 4 hours or so. Some people may notice that a particular fragrance lasts all day but by then it will not smell as it's supposed to. You must reapply once or twice a day. If a fragrance is only applied to the neck or behind the ears the fragrance will rise and disappear. It is important to apply a fragrance all over the body to ensure the scent lasts.
Oily skin holds scents much more than dry skin.
So those with dry skin need to reapply more often. Yes, since heat increases the intensity of a fragrance. There are certain fragrances that are more appropriate for summer and other stronger scents that would be better for winter use. A good guideline to follow is to wear lighter scents in the summer and stronger in the winter. Citrus scents are perfect for summer while orientals are better for winter.