Be careful with Deet, it will damage anything plastic that it touches.....Spandex, heartrate watches, etc..... I usually look for something that doesnt have deet, and then minimize the stopping in the evening in particular. If you are having the trouble during daylight hours, try to stay out of the shade, the mosquitos tend to hang out in the shade, and avoid bright sunlight.
Are you having problems now? I haven't noticed them lately.