DOVER — Monday was the first day of summer and the Division of Public Health took the day as an opportunity to remind Delawareans how to deal with excessive heat.

Public Health officials say a heat wave is when the temperature exceeds 95 degrees.

Part of the problem, according to spokeswoman Jennifer Brestel, is that bodies have less chance to recover during hot days and warm nights. That places everyone at risk for heat-related illness.

When temperatures and humidity are high, sweat ceases to evaporate and the body’s natural cooling system slows down or shuts down completely. Hot weather can cause heat exhaustion, heat stroke and severe respiratory conditions, which can be fatal.

Extreme heat is especially dangerous for seniors, young children, people with disabilities and people with breathing conditions and other chronic medical conditions.

Some of those conditions include asthma, chronic obstructive pulmonary disease and other respiratory and cardiovascular problems. Also at risk are people without access to air conditioning, fans or cooling shelters.

State officials recommend households make a heat-wave plan in case of a power outage. Air conditioners should be serviced and electric fans should be obtained now, before the heat rises to dangerous levels.

Cases of bottled water should be kept on hand and residents should listen to local news reports for the locations of community “cooling centers.” Those centers often public libraries or churches.

Also, during days of extreme heat, Delawareans should check on vulnerable members of their families and neighbors, Ms. Brestel said.

Pet owners are advised to have a plan for caring for pets. Animals at the greatest risk of stress from the heat include pregnant or lactating animals, very young and older animals, animals with darker coats, obese pets, short-nosed dog breeds and animals with chronic health conditions. Signs of heat stress can include panting, increased salivation, restlessness, and muscle spasms.

Other signs include increased heartbeat and body temperature, weakness, lack of coordination, bright red or pale and sticky gums, vomiting, diarrhea, and depression.

Owners can take steps to protect their pets by providing shade, plenty of cool drinking water while also avoiding unnecessary transportation and walking pets.

Delaware 2-1-1 connects Delawareans with services and support. Eligible callers can receive referrals to summer cooling and crisis assistance.

To prevent heat illness:

• Do not leave a child or pets alone in a parked car, even for a minute. Call 911 if you see a child or pet left unattended in a vehicle.

• Carry water with you and drink continuously even if you do not feel thirsty. Avoid drinks containing sugar, alcohol, or caffeine, which dehydrate the body. Check with a doctor before increasing fluid intake if you have epilepsy, heart, kidney, or liver disease, or if you are on a fluid-restrictive diet.

Avoid using salt tablets unless directed to do so by a physician.  Visit www.cdc.gov/healthywater/drinking/nutrition/index.html for more information.

• Stay indoors on the lowest floor possible. When outdoors, wear lightweight, light-colored clothing. Wear a hat or use an umbrella. Use sunscreen. Sunburn slows the skin’s ability to cool itself, and has been linked to skin cancer.

Avoid extreme temperature changes. Be careful trying to cool down too quickly; a cold shower immediately after coming in from hot temperatures can lead to hypothermia, particularly for the elderly and children. In these cases, cool water is better than ice cold water.

• Limit outdoor activity, especially mid-day when the sun is hottest. Work out or hold team practices early in the morning or in the early evening. A CDC course is available online.

Warning signs and suggested actions are:

• Address heat cramps by resting in a cool place and drinking plenty of water.

• Heat exhaustion is more severe, occurring when a person is overheated along with reduced or unbalanced intake of fluids. Symptoms include dehydration, fatigue, weakness, clammy skin, headache, nausea and/or vomiting, rapid breathing, irritability and fainting.

Move the person indoors or into shade. Loosen or remove the person’s clothing. Encourage the person to eat and drink. Get the person to a cool shower or bath. Call a doctor for further advice.

• Heat stroke occurs when the body can no longer cool itself, and can be a life-threatening event. Prompt medical treatment is required. Symptoms include: flushed, hot and dry skin with no sweating; high body temperature (above 103 degrees F, taken orally); severe, throbbing headache; weakness, dizziness or confusion; sluggishness or fatigue; decreased responsiveness; and loss of consciousness.

If heat stroke occurs, call 9-1-1 immediately. Get the victim indoors or into shade. Get the person into a cool shower or bath or wipe them down with continuously soaked cool washcloths while awaiting emergency responders.

For more information, visit the CDC.