Ordinary mosquitoes are enough of a problem on the Treasure Coast during the rainy season from June through October. Now we are being warned about daytime-biting mosquitoes that carry the dengue virus or the chikungunya virus. Both cause tropical diseases. Neither is usually fatal. But each can make you miserable for days or weeks. Fever, headache, nausea, extreme pain in the muscles and joints. Last year, 24 cases of locally acquired dengue fever were reported in Martin County. This year, health officials fear the chikungunya virus could also invade our area. A person goes to, say, the Caribbean, is bitten by a mosquito carrying one of the viruses, returns home, is bitten by another mosquito, and that mosquito transmits the virus to someone else. There is no vaccine to prevent either disease. But there are things we can do. Namely, drain and cover. Drain standing water from outdoor containers, including inflatable pools. That’s where mosquitoes breed. Cover your skin with clothes or repellent. Cover windows and doors with screens. Cover infants with mosquito netting. Ordinary mosquitoes are pests. Mosquitoes carrying either of these viruses are hazardous to your health. For 88.9 FM, this is Paul Janensch.