Suggest Treatment For Dizziness,blurred Vision And Tingling Sensation In Hands

Hello, After working in the intense heat for several hours I almost passed out. As I went to stand up everything started going black so I dropped back down and sat on the ground. Since this incident a month later - on random occasions I have suffered dizziness and not feeling right in my head. I have noticed it usually starts with extreme sleepiness, my vision gets a little blurred sometimes accompanied by very very mild tingling in my hands and feet. what do I need to do to get past these symptoms. I try to eat right and exercise regularly. I also have lost 22 lbs since Jan of this year. I drink high protein drinks twice a day. I am 47 and weigh 128lbs. I am not on medication of any kind and have considered myself to be healthy. Was checked by an inhome nurse 6 months ago and everything was normal then.