I did read that you do not want to drink the warm or hot water out of the faucet.
It has to do with the heated water sitting in the water heater tank - it will collect metals and toxins.
http://www.epa.gov/safewater/lead/lead1.html

[ Flush Your Pipes Before Drinking
Anytime the water in a particular faucet has not been used for six hours or longer, "flush" your cold-water pipes by running the water until it becomes as cold as it will get. (This could take as little as five to thirty seconds if there has been recent heavy water use such as showering or toilet flushing. Otherwise, it could take two minutes or longer.) The more time water has been sitting in your home's pipes, the more lead it may contain.

Only Use Cold Water for Consumption
Use only water from the cold-water tap for drinking, cooking, and especially for making baby formula. Hot water is likely to contain higher levels of lead.The two actions recommended above are very important to the health of your family. They will probably be effective in reducing lead levels because most of the lead in household water usually comes from the plumbing in your house, not from the local water supply.

Have Your Water Tested
After you have taken the two precautions above for reducing the lead in water used for drinking or cooking, have your water tested. The only way to be sure of the amount of lead in your household water is to have it tested by a competent laboratory. Your water supplier may be able to offer information or assistance with testing. Testing is especially important for apartment dwellers, because flushing may not be effective in high-rise buildings with lead-soldered central piping.]

http://everything2.com/index.pl?node_id=1413847


[The insides of a hot water heater contain metals that can, and do corrode. Some of the pipes in your home that are not made of PVC may have lead soldering. Hot water will dissolve metals, especially lead, much quicker than cold water will. Not to mention that over the years of daily use of drawing gallons throughout the day in cycles causes the water from the local utility, with all of it's impurities to collect and precipitate in the bottom of the hot water heater. This is a prime breeding ground for bacteria. Perhaps they cannot survive in an environment where the water is around 140°, but as soon as the water cools down enough due to a power outage or extended leave (if you turn off your water heater), all the necessary nutrients are there in an 80 gallon soup.]