McKesson Clinical Reference Systems: Pediatric Advisor 2002.1

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The leading cause of deaths and injuries to children at home is accidents. Scalding from hot water is one of the most dangerous of these accidents. Small children are busy and can get to sinks or bathtubs quickly. They can burn themselves severely before they can get out of the water. Infants are unable to move away from hot water if it is accidentally left on too hot.

The following chart shows just how dangerous hot water can be.

 
              Temperature      Time to Cause 
               of Water         a Bad Burn 
            -------------------------------------
               150°F (66°C)       2 seconds 
               140°F (60°C)       6 seconds 
               125°F (52°C)       2 minutes 
               120°F (49°C)      10 minutes 
            -------------------------------------

You can see from this chart that if your infant or young child should come into contact with hot water, the temperature of the water would make the difference between whether he or she gets burned or not. If your hot water heater is set at 150°F (66°C) and your child comes in contact with the hot water for just 2 seconds, your child will receive a burn bad enough to require medical treatment.

The following are some common questions and answers about hot water heater settings.

1. Q: If I turn the hot water heater setting down, won't I have trouble getting the dishes in the dishwasher and the clothes in the washing machine clean?

   A: No. The major soap manufacturers design their soap to work best in water between 120°F and 125°F (49°C to 52°C).

2. Q: Will my baby get more colds if the hot water isn't hot enough?

   A: No. Hot water has nothing to do with getting colds.

3. Q: Will we run out of hot water any sooner if we turn the temperature down?

   A: Yes, you will. But this may be a small price to pay to protect your child.

4. Q: Will I save any money on utility bills by turning down the temperature setting?

   A: Yes. On the average, for every 10°F (6°C) that you turn the temperature down, you will save 4% on the water-heating portion of your utility bill.

5. Q: I don't know where the thermostat of my hot water heater is, and I don't know how to tell at what temperature it is set. How can I tell?

   A: First measure the hot water temperature. The best way to do this is to measure it in the morning, before anyone in your home has used any hot water. Turn on the hot water at the kitchen sink and let it run for 2 minutes. Then, using either an outdoor thermometer or a candy thermometer, hold the thermometer in the stream of the water until the reading stops going up. If your water-heater setting is at a safe level (between 120°F and 125°F, or 49°C to 52°C), you don't have to do anything. There is no advantage to setting the thermostat below 120°F (49°C). If your hot water setting is too high, here are some tips on how to find the thermostat and turn it down.

   • Gas hot water heaters usually have a thermostat outside the tank at the bottom. Electric water heaters usually have either two panels screwed to the top and bottom of the tank or one panel along the side of the tank. Thermostats are located under these panels.
   • The thermostat should be set on the "low" setting or within the "energy efficient range." If the temperature at the kitchen sink is too hot at this setting, adjust the thermostat to a lower setting.

   After changing the thermostat setting, you can test the hot water temperature again about 24 hours later. If you test it in less than 24 hours, you will not get an accurate reading. Continue to test the water temperature and adjust the thermostat setting until the water is no hotter than 125°F (52°C). If you get it below 120°F (49°C), then turn it back up a small amount.

Please, take some time to think about the risk to your child from hot water in your home. Think about whether the convenience of having lots of very hot water is really worth the added risk that you might be taking with your child's health. Your child is no longer at significant risk for hot water burns by the age of 4 years. Then you can turn your hot water heater up to a higher temperature.