I wake up and decide to go fishing with my friends. It is a hot, sunny day. I wear a hat and sun safe clothing, however do not have breakfast prior to going fishing and take only a 600ml bottle of water with me. I was sitting at the water’s edge in ankle deep water, and did not notice the heat in the sun. At lunch time I starts to feel light headed and nauseous. Can you please explain (3) body systems to describe the anatomical and physiological processes taking place in my body while I was fishing.