What are the side affects of drinking to much warm lemon water?

No significant. Although you have not specified what is too much, generally the body will regulate the fluids . The excess water will be excreted in the form of urine. You will probably notice that you are urinating more than before. The temperature makes no difference. As far as lemon contents are concerned you will not see any change, but if you test it may turn out alkaline, which is nothing to worry.
Possibly stomach. stomach irritation due to consumption of large amounts of citric acid.
Acid. Lemmon juice is a mild acid and can be harmful to your teeth in excess.