In The Past Three Days Each Time I Go Into

In the past three days each time I go into our back yard in JAX, FL I start itching. First day it was on my hands and arms and I was just sitting there, not touching anything, but it was hot and the sun was on me. I came in and washed with soap and water and eventually it disappeared. Tonight I was out in sandals and my ankles and feet itch...I have not seen any fleas, but I've felt sick to my stomach as well.