I've been seeing a lot of patients lately who have tried to be out in the heat, and tried to do the right thing, but have come up short. Sometimes you have jobs that make you go outside. Or you play sports. Or garden. Whatever keeps you outside in 90+ degree heat, you need to take a few precautions. Sunblock, of course, see my blog on the dangers of certain types of sunscreens for more information on which ones to buy.

Most importantly, you need to be hydrated. And water doesn't cut it.

Are you shocked that I'm telling you that drinking water is bad for you for the heat? Here's why:

Your body tries to regulate your temperature to prevent overheating by sweating and evaporation. Have you noticed your sweat is salty? That means you don't have pure water coming out--you have electrolytes too. If you sweat electrolytes, but replace with water, you will dilute your electrolytes and lead to imblances that can cause cramping, or worse, heart abnormalities and altered mental status.

The outside temperature for which your body can maintain a normal body temperature is 84 degrees. Higher temps and/or humidity can increase your body temp.

You are at higher risk if:
  1. Physical activity in hot/humid weather
  2. Extremes of age
  3. Excessive clothing
  4. Dehydration
  5. Cardiovascular disease
  6. Skin disorders (i.e. schleroderma or severe burns)
  7. Obesity
  8. Medicines
What are heat cramps?
Cramps tend to occur later in the day when relaxing or taking a cool shower after having been in the heat. Normal body temperature. Involve calves, thighs and shoulders most commonly.
-Prevent by injesting salt and water (electrolyte solutions like gatorade work well)
-Treatment: Rest in cool environment, Salt replacement (electrolyte solutions or IV saline)

Heat exhaustion:
Extreme fatigue, profuse sweating, dizzy, nausea/vomiting, even diarhea. Dull headache. Body temperature normal or slightly elevated. Most common heat illness that usually occurs during heat waves. Lots of sweating.

Heat stroke:
Least common, most serious. Suspect if altered mental status and elevated body temp after having been in hot/humid environment. Alcoholics and elderly particularly vulnerable. Hot DRY skin.
-Treat with COOLING not fluids. Too many fluids can lead to congestive heart failure. (of course call 911 and get the patient to an ER ASAP)
---Remove clothes. Spray water onto skin, don't apply ice directly to skin. Fan patient. Ice packs to underarms and groin. Some oral electrolyte solutions if able, but don't overdo.

You need to drink electrolyte solutions such as gatorade, propel, powerade, etc... or drink water, eat crackers (salt) and bananas (potassium).

How much should you be drinking to prevent illness?

As much as you can, as often as you can, as long as you are exposed to heat. As long as you are making large amounts of dilute urine, you are drinking enough. If you aren't urinating or are urinating dark urine, you need to drink more.