There are many severe consequences of exceeding the proper temperature level in broilers breeding. They typically come from the inappropriate diet that is caused by increased water consumption due to higher temperature level. At the level of ambient temperatures above 18˚C, the water consumption by older broilers is increased by 7% per each 1˚C. In the same time each 1˚C above 25˚C reduces the feed intake by 1.5 %. Reduction of feed intake in the first place causes the lower mass gains. It also very often results in higher demands for vitamins as typically they are supplied with feed of which intake is decreased.