Severe Weather Toolkit
1.7 Excessive Heat and Drought
All areas of Texas can experience periods of excessive heat and drought. Excessive heat and drought conditions may be pre-cursers to wildfires. Schools should plan for these periods and limit outdoor activities during the hottest parts of the day, typically considered mid to late afternoon. Students with medical conditions may be extremely susceptible to heat stroke or heat exhaustion. Plan to provide plenty of drinking water and shade to keep students and staff hydrated and out of the sun.
Excessive Heat Outlook
The National Weather Service (NWS) issues an excessive heat outlook when there is a potential for an excessive heat event in the next three to seven days. The outlook is intended to provide information for those who need considerable lead-time to prepare for the excessive heat.
A heat advisory is typically issued within 12 hours of the onset of extremely dangerous heat conditions. Generally, a heat advisory is issued when the maximum heat index temperature is expected to be at 1000 or higher for at least two days, and night time air temperatures will not drop below 750; however, these criteria vary across the country, especially for areas that are not accustomed to dangerous heat conditions.
Excessive Heat Watch
An excessive heat watch is issued when conditions are favorable for an excessive heat event in the next 24 to 72 hours. A watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.
Excessive Heat Warning
The NWS issues an excessive heat warning within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this warning is when the maximum heat index temperature is expected to be 1050 or higher for at least two days and night time air temperatures will not drop below 750; however, these criteria also vary across the country, especially for areas not accustomed to extreme heat conditions.
Heat Related Illness
Heat-related illness, sometimes referred to as heat stress, can result from a combination of high temperatures, high humidity and physical exertion that affects the body's cooling system. Air velocity can also contribute to heat-related illness. Stale, stagnant air or hot wind increase stress on the body from heat, whereas a cool breeze can reduce the risk of heat-related illness. To prevent heat-related illness, it's important to gradually acclimate to hot weather, stay hydrated, watch for signs and symptoms of heat stress and plan for rest periods. The two most common types of heat-related illness are heat exhaustion and heat stroke.
One type of heat-related illness or heat stress is referred to as heat exhaustion. Heat exhaustion is a condition caused by the depletion of body fluids and electrolytes causing the body to become over-heated. Symptoms of heat exhaustion include:
- Excessive sweating
- Pale skin
- Elevated body temperature
Heat exhaustion is easily treatable as long as it's onset is recognized early and first aid is rendered quickly. The following actions should be taken if heat exhaustion is suspected:
- Move the victim to a cooler and/or shaded location
- Lay the victim down and elevate their feet
- Loosen clothing and fan vigorously
- Give the victim water or electrolyte-balanced fluids like sports drinks, slowly
- Seek medical attention if the victim doesn't improve
Heat stroke is a form of hyperthermia, a condition in which the body's temperature is elevated dramatically and is the most serious type of heat-related illness. Heat stroke occurs when the body's natural cooling mechanism stops functioning and the victim stops sweating sufficiently. It is therefore important to recognize the symptoms of heat stroke quickly, to help treat victims. Symptoms of heat stroke include:
- Little or no sweating; hot, dry and red blotchy skin
- Dangerously high body temperature, greater than 1040
- Extreme dizziness and nausea
- Confusion or delirium
- Convulsions and/or seizures
- Collapse or loss of consciousness
Heat stroke is a genuine medical emergency that can be life-threatening. If heat stroke is suspected, seek medical care immediately. The following actions should be taken if heat stroke is suspected:
- Call 911 immediately
- Reduce the victim's body temperature by placing damp towels around the neck and under the arms
- Do not force the victim to drink or eat
Both heat exhaustion and heat stroke are preventable. When extended outdoor activity or physically strenuous indoor activity is planned, both staff and students should be encouraged to:
- Wear loose and light colored clothing and sunscreen
- Stay well hydrated—drink plenty of water or drinks containing electrolytes (caffeinated beverages should be avoided)
- Take frequent rest breaks
Excessive Heat Resources
Unusually dry weather can lead to drought. According to the National Drought Mitigation Center, "drought originates from a deficiency of precipitation over an extended period of time—usually a season or more—resulting in a water shortage for some activity, group, or environmental sector".1
Long periods of drought can affect water supplies to the community and the school. During a drought, voluntary (or in extreme situations, mandatory) water conservation measures may be implemented by state and local officials. These conservation measures may directly impact school operations and the continued ability to meet the needs of students.
Water Conservation Strategies
- Curtailing all non-essential water use activities
- Altering watering schedules for athletic fields and school grounds
- Installing drought tolerant landscaping
- Curtailing washing of school buses and fleet vehicles
- Restricting water use to clean outside surfaces such as sidewalks, driveways and tennis courts and outdoor furniture
- Implementing a moratorium on filling of swimming pools
- Installing low-flow toilets
Schools should also consider that an extended or severe drought could lead to drinking water supply shortages or contamination of the drinking water. In the event a boil-water notice is issued by local authorities, schools may need to restrict the use of drinking fountains and rely on bottled water instead. Cafeteria operations may be affected as well. School administration should consult with the local public health department for guidance on food services such as meal preparation, clean-up and sanitation. It may also become necessary to close schools.
Drought and dry weather can make it difficult to fight even small fire outbreaks. Communicate with the fire department and local officials to monitor any changes in fire protection, burn bans and red flag wind conditions. In addition, prepare staff and students for potential protective actions.
1 National Drought Mitigation Center, http://drought.unl.edu/DroughtBasics/WhatisDrought.aspx