"Hot water is typically described as approximately 110 to 140 degrees," says Channa Ovits, M.D., FAAD, a Westchester, New York-based board-certified dermatologist at Westmed Medical Group, a Summit Health Company. But in terms of a shower, you should never tiptoe over 120 degrees, due to the chance of a burn injury.
Recommended Water Heater Temperature for Safety and Efficiency. Many experts, including the U. S. Department of Energy and the Environmental Protection Agency, recommend that your water heater be set to about 120 degrees Fahrenheit.
Hot Water Baths
For those who relish a hot water bath to unwind, dermatologists suggest a peak temperature of around 44.4°C (112°F). However, it is advised not to exceed 48.9°C (120°F), as extreme temperatures can lead to skin irritation or even burns.
And while there is a very slight risk of promoting legionellae bacteria when hot water tanks are maintained at 120ºF, this level is still considered safe for the majority of the population. If you have a suppressed immune system or chronic respiratory disease, you may consider keeping your hot water tank at 140ºF.
There's no absolute rule for how hot a shower should be, but most doctors advise keeping water below 110 degrees. Too hot and you risk stripping the skin of its natural oils leading to dry, itchy skin.
Optimal Shower Temperature
Hot water is typically described as somewhere between 110°F and 140°F. However, you should never turn your shower or bath water anywhere near 120°F due to the risk of a serious burn injury. Cold water is generally defined as 60°F to 80°F, though it can be even lower.
Even though a water temperature of 110° F is 'relatively-safe', exposure can be painful; the human pain threshold is around 106-108° F. As the chart reproduced below reveals, the severity of a burn is a function of the temperature of the water and the duration of the exposure and the condition of the skin.
Many kayak anglers follow the 120 rule. This rule states (in Fahrenheit) that the air temperature plus water temperature should be greater than or equal to 120. With the caveat that water temperatures should be at or greater than 60 F.
Researchers cranked up the temperature on volunteers to find out. A new study suggests that once temperatures hit 104 to 122 degrees, our bodies may stop working optimally.
Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns.
"Hot water is typically described as approximately 110 to 140 degrees," says Channa Ovits, M.D., FAAD, a Westchester, New York-based board-certified dermatologist at Westmed Medical Group, a Summit Health Company. But in terms of a shower, you should never tiptoe over 120 degrees, due to the chance of a burn injury.
So, What Is the Ideal Shower Temperature? “Luke warm,” says Anolik. Many experts agree the tepid temperature feels slightly warm compared to your body temperature, and falls somewhere between 98º and 105º F.
According to Centers for Disease Control and Prevention (CDC), water temperatures ranging from 130 to 140 degrees Fahrenheit(°F) can eliminate most of the harmful bacteria. However, be warned that these high temperatures can also increase the risk of scalding.
The Occupational Safety and Health Administration (OSHA) recommends a recommended hot water temperature of at least 122 degrees to prevent the growth of harmful bacteria. So, while setting the temp to 120°F may save on energy costs and avoid scalding, it's ideal to keep things a bit warmer for safety.
The easiest way to prevent burns from hot tap water is to turn down the setting on your hot water heater to 49 °C (120 °F).
The best temperature setting for a hot water heater is between 120 and 140 degrees. Below 120 degrees, bacteria can develop in the stagnant water sitting in the tank. Above 140 degrees, the water is so hot that you and your family members can be at risk for scalding in as little as two seconds.
Given enough water and access to shade to avoid sunstroke, humans can survive for several hours in dry heat, up to temperatures in the 120s. (This is not doctor-recommended.)
The best room temperature for sleep is approximately 65 degrees Fahrenheit (18.3 degrees Celsius). This may vary by a few degrees from person to person, but most doctors recommend keeping the thermostat set between 65 to 68 degrees Fahrenheit (15.6 to 20 degrees Celsius) for the most comfortable sleep.
The hottest place on Earth is Furnace Creek in Death Valley, California (USA), where a temperature of 56.7°C (134°F) was recorded on 10 July 1913.
Cold shock can be just as severe and dangerous from water temperatures of 50-60F (10-15C) as it is from water at 35F (2C). Gasping for a breath or rapid breathing from sudden immersion can be triggered by water as warm as 77F (25C).
The NEC 120% rule limits the size of additional power sources (PV or battery) to within an acceptable safety limit based on the equipment label rating. In this case, the PV breaker would be limited to a maximum of 40 amps. 200 amp rating x 120% = 240 amps. 240 amps minus the 200 amp main breaker = 40 amps max.
The boiling point of water is 212 degrees Fahrenheit or 100 degrees Celsius at sea level. That means in most places this is the temperatures of boiled water. However, as you rise above sea level water will boil at a lower temperature.
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting.
According to most dermatologists, the ideal shower temperature is anywhere between 98°F (37°C) and 104°F (40°C)—and no more than 105 °F (41°C).
Anything above 120°F is shown as scalding. Please also note that 120°F = 48.8888… °C or approximately 50°C.