I took my son turkey hunting for the first time last week..I bought an extra Therma cell at a garage sale for 1.00 { -: When I heard the mosquitoes I whispered for him to turn his Thermo on..After an hour I ask him how it worked..he said great..then he turned it off..like maybe there was no mosquitoes anyway..The mosquitoes moved in and he quickly turned it back on..and again they disappeared..He is now a beleiver of the Thermacell..
I love mine and always keep stocked up on refills.I liev in Florida..it's a must.