Mosquito repellent spray with 30% DEET provides on average 6 hours of protection against the most common mosquito species (Culex spp). For some tropical mosquito species, the protection time may be shorter, on average 3 hours against the yellow fever mosquito (Aedes spp) and 4 hours against the malaria mosquito (Anopheles spp). Factors such as temperature, humidity and perspiration may affect the efficacy of the product.