I often get severely dehydrated and feel dizzy/faint but i haven't died or fainted or been hospital, how do i survive so well? i even exercise in heat

Survival of Fittest: You have survived on luck or perhaps a contributing factor of genetics. But Hey! Take care of yourself and don't push it to the limits like this! Heatstroke is a real phenomena which can take your life! Listen to your body! Drink lots of water and remember this... Dizziness and faintness while exercising in the heat is a first sign of heat exhaustion, so sit down, cool down drink water!