There’s a persistent urban legend that if you drink cold water, especially after eating, you’ll get cancer. The theory, which has been widely circulated via email, suggests that cold water solidifies fats you have just consumed, quickly causing toxins to create cancer in your body. Sites devoted to proving or disproving urban legends, like snopes.com, have defeated this theory quite effectively. It is not unhealthy to drink cold water, though in some cases, tepid or room temperature water may be a better choice.
One theory, upon which medical researchers have varying opinions regards whether drinking cold water is as good for you as drinking tepid water, particularly when you are exercising. Some doctors suggest that room temperature or body temperature water is better than cold water, because the body has to expend energy to heat cold water to body temperature, resulting in some water loss. On the other hand, some doctors say that after physical exertion, you should drink cold water since it will help cool the body more effectively than room temperature water.
What is clear is most people who drink cold water are likely to consume more of it, since it tends to taste better and is more satisfying. Even if drinking water right out fo the fridge results in marginal water loss, the extra water you will probably drink will help make up for this. There are some instances where you shouldn’t use cold water, but generally this doesn’t apply to drinking.
If you are attempting to help bring down a fever, or assist someone with sunstroke (animal or person), you should not immerse that person or animal in cold water. Instead you should use lukewarm water, or even slightly warm water. Cold water can provoke chills, which may actually raise body temperature. Although baths can be a helpful way to bring down high fevers, you especially want to avoid allowing someone to shiver or get chilled. If people with fevers drink water that is very icy, they may also get chilly, so lukewarm or tepid water may be a better choice.
There are a number of other urban legends associated with the amount of liquids and the type of liquids you consume. For instance people are told that coffee, tea and sodas deplete water from their bodies. Actually, people who routinely drink caffeinated beverages retain about two-thirds of what they drink, and this can be counted as part of daily fluid intake. Another “myth” regarding water is the eight, eight ounce (.24 l) glasses of water are needed daily. While this amount of water won’t hurt you, daily intake of food usually provides about half the amount of needed fluids. Most people can get by with drinking about 32 ounces (approx. 1 liter) daily.
The best indicator of whether your body is getting enough water is urine color. If your urine is dark yellow, chances are you’re not getting enough water. If you pass clear to very light colored yellow urine, your fluid intake is adequate. Remember that urine color in the morning will always be a little darker. Another indicator is thirst. When your body sends you “I’m thirsty” signals, have something to drink, but don’t worry about whether you should drink cold water or warm.