(CBSDFW.COM) — The first day of summer is bringing temperatures that will feel like 105 to 110 degrees, resulting in the first Heat Advisory of the season being issued for the majority of North Texas.

A Heat Advisory means that during the hottest part of the day the heat index values are expected to meet or exceed 105 degrees and with those numbers rising to dangerous levels there are risks for heat exhaustion and heat strokes.

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Untreated heat exhaustion can progress to heatstroke suddenly and cause unconsciousness within minutes. Older adults, the very young, and people with mental illness and chronic diseases are at highest risk in the extreme heat. However, even young and healthy people can be negatively affected during very hot weather.

According to CBS 11 Meteorologist Jeff Ray North Texans should, “Expect another week (next week) of unsettled weather before the typical summer pattern of “hot and dry” locks in. Storms will be less frequent and heat more prevalent.”

First-responders with MedStar Mobile Healthcare treated more than 20 people Thursday for heat related illnesses.

Heat stress, heat fatigue, heat cramps and heat exhaustion are all forms of hyperthermia. It’s important to find ways to stay cool and know the signs of hyperthermia. In addition to feeling uncomfortably hot, you may also experience: dizziness, weakness, nausea, thirst or a headache.

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When both the temperature and humidity are high you’re body can’t cool itself through natural sweat functions. Doctors say those days can be especially dangerous for people moving about or working outdoors.

Medical experts say those wanting to exercise outdoors should reschedule the activities for early morning or evening. If possible, anyone working outside should schedule frequent rest breaks in shaded or air conditioned environments.

While temperatures are oppressively hot North Texans are being encouraged to:

  • Hydrate: Drink plenty of water during the day, especially if you are engaged in any strenuous activity.  Sports drinks are a good choice if you’re exercising or working in hot conditions, but water is a good way to hydrate as well.
  • Ventilate: Stay in a place where there is plenty of air circulating to keep your body cool.  If you are indoors and don’t have access to air conditioning, open windows and use a fan.
  • Cover Up: Wear light-colored and loose-fitting clothing to avoid absorbing the sun’s light and trapping heat.  Wear a hat to shield yourself from the sun, but once you feel yourself getting warm, remove any items covering your head which can trap heat close to your body.
  • Limit Activity: Heatstroke can occur in less than an hour when you are participating in strenuous activity during a hot day.  If you feel yourself getting hot or light-headed, stop your activity and rest in a cool place out of the sun.  Be sure to drink water or a sports drink before, during, and after any strenuous activity.
  • Check on Loved One’s: The elderly are especially vulnerable to heat related emergencies.  Many elderly residents are not aware of how hot it may get in their residence.  Call on older friends and family members regularly to assure they are doing okay.
  • Kids in Hot Cars: Each summer, police, fire departments and EMS respond to calls where a child is left in a hot car. DO NOT leave children unattended in cars and be sure your vehicle.

Experts with the SPCA of Texas say pet owners also need to be mindful during the summer months.

Pets should have fresh, cool water in a tip-proof bowl — and it’s not a bad idea to add ice. Pets should never be left in a parked car, even with the windows cracked. It takes only minutes for a dog or cat to suffer a heat stroke.

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The SPCA says if owners leave their pets outside they must make sure the animal has shelter available to protect it from extreme temperatures and inclement weather. To help pets cool off during summer owners can also provide a wading/kiddie pool filled with water.