Do You Need Hot Water To Wash Your Hands And Kill Germs?


Keeping hands clean is one of the best ways to prevent the spread of infection and illness. Chances are that what you think you know about hand washing… might be wrong…

During cold and flu season, people are especially concerned about germs, and avoiding them. People in the United States typically wash their hands seven times a day, and most do it at a much higher temperature than necessary to kill germs and most probably do not wash long enough.

It is true that heat kills bacteria, however the hot water temperature necessary to kill them would be far too hot for you to tolerate.

To disinfect water for drinking, boiling water at 212°F will kill most pathogens. The hot water temperature in your hot water tank at home is typically set around 120°F, a temperature which will scald the skin if left on too long, and a temperature which may only kill ‘some’ pathogens under sustained scalding contact.

Amanda R. Carrico, a research professor at Vanderbilt in Tennessee said to the Daily News of National Geographic, that her team found “no evidence that using hot water that a person could stand would have any benefit in killing bacteria.” Even water as cold as 40°F appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed, and dried properly.

Most people believe that using hot water is more effective than warm, room temperature, or cold water, when it comes to killing germs while washing clothes or hands. There is a strong cognitive connection between water temperature and hygiene, although not entirely accurate. Hot water is actually more associated with comfort than with health.


The right way to wash your hands

Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.

Lather your hands by rubbing them together with the soap. Be sure to lather the backs of your hands, between your fingers, and under your nails.

Scrub your hands for at least 20 seconds. Need a timer? Count 1,001 – 1,002 – etc.

Rinse your hands well under clean, running water.

Dry your hands using a clean towel or air dry them.


When you should wash your hands

Before, during, and after preparing food

Before eating food

Before and after caring for someone who is sick

Before and after treating a cut or wound

After using the toilet

After changing diapers or cleaning up a child who has used the toilet

After blowing your nose, coughing, or sneezing

After touching an animal, animal feed, or animal waste

After touching garbage

As you touch people, surfaces and objects throughout the day, you accumulate germs on your hands. In turn, you can infect yourself with these germs by touching your eyes, nose or mouth. Although it’s impossible to keep your hands germ-free, washing your hands frequently can help limit the transfer of bacteria, viruses and other microbes.

Keep in mind that antibacterial soap is no more effective at killing germs than is regular soap. Using antibacterial soap may even lead to the development of bacteria that are resistant to the product’s antimicrobial agents — making it harder to kill these germs in the future.


  1. That last paragraph is interesting. Why is there anti-microbial soap if it is only as effective as regular soap?

  2. If you want a more fun way to time your hand washing sing happy birthday. It takes about 20 seconds.

    1. That’s exactly the recommendation from the CDC website… whatever it takes to remember to wash more than just a few seconds…

    2. Mary Had a Little Lamb also works as does the ABC song. BTW, it’s now found that washing for 30 sec is better.

  3. The thing I always find interesting is that most people turn off the water with there nice clean hands that they just turned the water on with before washing. So now those germs have just found there way back onto your hands. I try to always use a paper towel to turn the water off with.

    1. That’s a good idea, plus, something that people don’t do often enough is to clean those handles regularly (along with the sink itself). Those handles get full of invisible (and visible) grime and germs…

    2. When you finish washing your hands, also wash the faucet and anything else you touched.

  4. The hot water may not kill the germs, but soap doesn’t lather much in cold water.

    1. You’re right about that ;) Plus, who wants to wash their hands in c-c-cold water…

      …I’m just pointing out here that ‘technically’, you’re not clearing off the germs from your hands with hot water (because we cannot stand water that would be hot enough to actually kill most of the germs). Instead it’s simply the combined action of rinsing-washing long enough with water, and the scrubbing action with your hands, along with the added cleaning power of soap…

  5. When using a public washroom, use a paper towel to grasp the door handle when leaving. After the door is open, discard the towel in the trash can. Important: If the trash can is not next to the door, throw the towel on the floor near the door, every time you go there, until the establishment moves the trash can next to the door.

    1. Blinkie, such good advice re throw paper towel on floor.

      yrs ago, my girlfriend advised me this was what she did, use towel to open door, and if no garbage close by, pitched it behind door after opening. at first I did think she was being nasty, but shortly after saw her wisdom and been doing same myself. in the past ten yrs, it is quite amazing how many establishments have learned to put a garbage can behind the door.

  6. for sure re taps, especially in public. if stuck without a paper towel to grab taps/door, use your sleeve. in fact, I often think drying one’s hands on pants might be less germy than grabbing a tap..sigh

    re the washing hands in cold water, pretty sure from own experience it works.

    as a youngster on a farm, without running water, we always had a bucket of cold water to scoop water fr and wash hands. hands were washed with bar of soap and cold water (often). I cannot recall any of us getting sick etc. (until we moved to the city and got all those city germs etc…)..

  7. As a RN for 20 years we were taught a lot about handwashing. While warm water is more comfortable for the minute. It is not in the long run because the only long term benefit you will get is very dry skin. Especially if you are washing your hands multiple times a day. Also remember there are a lot of microbes that hand sanitizer does not kill. The only thing that is truly effective is washing your hands with soap and water. It is the scrubbing motion and the soap that cleans them. Also make sure you get under and around your fingernails and any rings you have on. They are the main places bacteria like to be.

  8. FOLKS from a stand point of washing hands use cold water if you have soap good if not after drying use some germ x , that cleans and also kills germs.

    one thing not mentioned is when I go to eat I USE GERM X AND WIPE A RESTAURANT TABLE DOWN AND THE TOPS OF THE CHAIRS AND THE SALT AND PEPPER SHAKERS. THAT stops lots of flu’s and colds and germs.

    Thanks for reading MERRY CHRISTMAS Mark

  9. In the event of an emergency and water cannot be found to wash your hands and you need to be clean carry with you some plastic gloves like a doctors office uses. I keep several pairs in my truck and my Bug Out bags even my Scout Bag. The reason being is I have been first response to several car accidents and couldn’t “wash” so I tossed on a pair of disposable gloves to keep their blood and germs off me. This has helped me help others in need of medical attention. Granted it is very important to understand that if you “treat” an emergency situation you could be sued if you do damage to others but I have taken that risk and just went ahead and helped. Sometimes time is not on your side and washing might be out of the question so stock up on a box of good disposable gloves, they might save a life and they defiantly will keep the germs off your hands.

  10. Washing your hands with soap and water doesn’t kill germs, it washes them away. The smaller the germ colony the less likely it is to cause disease. The CDC recommends an 60-95% alcohol based sanitizer not an anti-bacterial like Triclosan.

    1. As a water scientist, you are the only comment that I read with the point in all this. Soap and water are used to wash away the germs, NOT necessarily to kill them. Remember, we aren’t trying to make more germs resistant, we are just trying to remove them so that they can then be killed by nature…the sun, drying out, etc. Remember that next time you reach for something that says it “kills germs in the air”… you are breathing that air you just sprayed…

  11. Try to avoid the hand dryers… think of all the bacteria and viruses lurking in the air of a bathroom… then after washing your hands, you turn on the dryer and that air is blown on your hands… the air which is sourced from where??? A germ laden bathroom… learned this from a medical type…

    1. Anonymous, good point. yuck. I knew there was a reason I thought maybe wiping them on your jeans wasn’t such a bad idea. in fact, now you mention this, I might be real good idea.

  12. i make my own hand sanitizer that moisturizes. i bought some in a spray bottle, shaped like a large pen, that holds about half an ounce. when i used it up, i replaced the liquid with 70% rubbing alcohol (has to be at least 62% to kill germs) and 3-4 drops of olive oil. i have very dry hands with psoriasis, but the olive oil makes them very soft, much better than washing with soap and then applying hand creme. i tuck the container into the outer pocket of my purse, and the “pocket clip” keeps it in place so it’s always handy.

  13. It’s awful when you see someone leave the toilets who haven’t washed their hands then that meeting you set up includes this person and as professional courtesy they extend their hand to shake yours … yuk. And these are the people you know about.

  14. Ever since I was a grade school child my mother taught us to use your foot to hit the handel of the toilet. Now a days some restrooms have the sensor to flush it but if not…use your foot!

    1. Use TP or a paper towel. I use a paper towel to open the door to get out of the restroom. Washing your hands doesn’t do much good if someone before you didn’t and left germs or whatever on the handle/knob.

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