Can Extreme Heat Cause Weight Gain Due To Fluids In Leg And Stomach?

I am hoping you can assist, I have gained 7 kilos in 5 days and seems to be fluid as my ankles legs and stomach areas are all swollen and fluid like when I press into it. I have just come back from a holiday for those 5 days and was in extreme heat that I am not used to...my question is could this be from the heat and is should I go and seek medical advice now?? I am worried that it may be dangerous....please help!!!!