SUMMER EXHAUSTION: Cosmopolitan magazine examines why it is we get so tired in dog days of summer.

· Summer fruits: Fruits such as cantaloupe and pineapple have a high glycemic index which quickly boosts energy just quickly as it sucks it all away afterwards.

· Swimming in a pool: Chlorine can irritate sensitive sinuses and sinusitis can lead to exhaustion.

· Too much AC: "When you're chilly, your body works to produce heat, and that consumes energy," says Marc Riedl, MD, assistant professor of medicine at UCLA.

· Outdoor happy hours: Drinking wine or beer, in combination with outdoor allergies, serve as a double whammy for fatigue.