SWAW, Day 5: Heat Waves

It's Severe Weather Awareness Week in MN and WI, which means its time to start going over what everything is again and what precautions to take when severe weather strikes. While no major heat is in the forecast, some severe weather might be, so now is as good as time as any to relearn what we do in summertime, like how we have to relearn the winter warnings (and how to drive) in the winter. Remember, throughout the summer we'll cover it the best we can on Facebook, Twitter, and now Blogger. Today's topic, brought to you by the National Weather Service, is Heat Waves -- I've also included what watches, warnings, and advisories there are for heat.

Heat Waves (can also find more from this NWS Publication on Heat Waves)

Watches...
Excessive Heat Watch: In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport is expected to reach 105 or greater for 1 day, or the maximum heat index is expected to reach 100 or greater and an overnight low temperature no cooler than 75 for 2 days in a row. In addition, the Heat Watch/Warning System must recommend a watch.
Excessive Heat Watch: Outside Hennepin and Ramsey counties: Maximum heat index reaches 105 or greater and a minimum heat index of 75 or greater for at least 48 hours.

Warnings...
Excessive Heat Warning: In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport reaches 105 or greater for 1 day, or the maximum heat index reaches 100 or greater and the overnight low temperature is no cooler than 75 for 2 days in a row. In addition, the Heat Watch/Warning System must recommend a warning. A warning may also be issued if advisory criteria are expected for 4 days in a row.
Excessive Heat Warning: Outside Hennepin and Ramsey counties: Maximum heat index reaches 105 or greater and a minimum heat index of 75 or greater for at least 48 hours. A warning may also be issued if advisory criteria are expected for 4 days in a row.

Advisories...
Heat Advisory: In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport is expected to reach 105 or greater for 1 day, or the maximum heat index is expected to reach 100 or greater and an overnight low temperature no cooler than 75 for 2 days in a row.
Heat Advisory: Outside Hennepin and Ramsey counties: Maximum heat index reaches 100 and/or the maximum temperature reaches 95 or higher.

Minnesota's Deadliest Weather Factor Since 1990...
The second greatest number of weather fatalities in Minnesota since 1990 has been due to excessive heat. Fourteen people have died from high heat and humidity. Only flooding has killed more people in the last 18 years.

Wisconsin's Deadliest Weather Factor Since 1982...
The greatest number of weather fatalities in Wisconsin since 1982 has been due to excessive heat. 116 people have died from high heat and humidity. This total is more than tornadoes, flooding, blizzards or anything else. The 1995 summer heat waves hold the record as the number one weather-related killer in Wisconsin since it became a state in 1848. Most deaths occurred in the major urban areas in southeast Wisconsin, but there have been a number of fatalities in the rest of the state as well.

Fortunately, there were no deaths last year from excessive heat in either WIsconsin or Minnesota.

In the last 10 years, a national average of 219 people have died as a result of health problems directly related to excessive heat. Considering this death toll, the National Weather Service has stepped up its efforts to more effectively alert the general public to the hazards of heat waves.

Based on research findings, the National Weather Service devised the Heat Index (HI). It is an accurate measure of how hot it really feels when the relative humidity is added to the actual air temperature. It is important to note that since heat index values were devised for shady, light wind conditions, exposure to full sun can increase values by up to 15 degrees.

Heat disorders generally have to do with a reduction or collapse in the ability of the body to shed heat by circulatory changes and sweating. In other words, a chemical imbalance caused by too much sweating. When heat gain exceeds the level the body can remove, or when the body cannot compensate for fluids and salt lost through perspiration, the inner-core temperature of the body begins to rise and heat-related illnesses may develop. Ranging in severity, heat disorders share one common feature: the individual has over-exposed or over-excerised for his/her age and physical condition in the existing thermal environment.

Sunburn, with its ultraviolet radiation burns, can also significantly retard the ability of skin to shed excess heat.

Safety tips...
The National Weather Service will issue advisories or warnings when the heat index is expected to have a significant impact on public safety. The common guidelines for the issuance of excessive heat warnings is when the maximum daytime index is expected to reach 110 or 115, and the nighttime low temperature does not fall below 75 or 80 degrees.

Here are some tips to follow to ensure that heat-related problems do not impact you...

• Slow down. Strenuous activities should be reduced, eliminated or rescheduled to the coolest time of the day. Individuals at risk should stay in the coolest available place, not necessarily indoors. Dress for summer. Lightweight, light-colored clothing reflects heat and sunlight and helps your body maintain normal temperatures.
• Put less fuel on your inner fires. Foods such as proteins that increase metabolic heat production also increase water loss.
• Drink plenty of water or other non-alcoholic fluids. Your body needs water to keep cool. Drink plenty of fluids, even if you don't feel thirsty. However, those who suffer from epilepsy, heart, kidney or liver disease, are on fluid restrictive diets, or have a problem with fluid retention should consult a physician before increasing their consumption of fluids.
• Do not drink alcoholic beverages.
• Spend more time in air-conditioned places. Air conditioning in homes and other buildings markedly reduces danger from the heat. If you cannot afford an air conditioner, spending time each day in an air-conditioned environment during hot weather affords some protection.
• Be careful not to get too much sun. Sunburn makes the job of heat dissipation that much more difficult.