It's hot outside! With temperatures over 100 heat stroke can creep up on you. It can be difficult to remember and drink water while doing outdoor activities but it is absolutely necessary in order for your body to cool itself. Here are the 10 signs of heat stroke.

1. Incredibly Hot Skin - Incredibly hot, red skin is one of the most popular signs of heat stroke. If your skin is hot to touch and you have an internal body temperature 105 degrees or higher, you will need to see a doctor as soon possible. A simple sunburn will also present this symptom (red, hot skin) but the situation becomes dangerous when your body temperature stays higher than 105.

2. Dizziness and Fainting - In addition to an internal body temperature greater than 105 degrees Fahrenheit, dizziness and fainting are the next most common symptoms of heat stroke. If you’ve spent several hours in the sun and you experience this symptom, contact your doctor immediately and make sure you drink lots of water in the meantime.

3. Extreme Fatigue - Spending a day in the sun can be exhausting at the best of times, however, if you’re experiencing some of the other symptoms on this list along with extreme fatigue, it may be a sign of heat stroke. If this is the case, it’s always best to seek medical help, just in case your heat exhaustion has progressed into heat stroke.

4. Nausea - Nausea is another indication that your heat exhaustion has progressed into heat stroke. A constant nauseous or uneasy feeling in your stomach (especially combined with dizziness) may mean your condition is worse than you initially thought. Drink lots of water to help treat the nausea and, as always, contact your doctor for assistance.

5. Vomiting - Feeling nauseous is one thing, but actually vomiting is another. If your nausea has progressed into vomiting, this is a definite sign of heat stroke and it’s critical that you seek medical attention immediately. Drink as much water as possible on your way to seek help.

6. Rapid Heartbeat - A rapid heartbeat after spending time in the sun can be an indication of a serious problem. If you’re experiencing some of the other symptoms on this list in addition to a rapid heartbeat, you will want to make sure you get checked out immediately. When it comes to the heart, you don’t want to take any chances.

7. Mental Confusion - Individuals who have heat stroke often feel dizzy but mental confusion is also a popular symptom. If you’re having difficulty thinking, remembering or focusing, it may be an indication that you’re suffering from heat stroke. If this is the case, contact your doctor or seek medical help as soon as possible.

8. Seizures - Seizures are a very serious (and very dangerous) symptom of heat stroke that requires immediate medical attention. This symptom often presents itself abruptly and offers few warning signs. If someone you know has suffered a seizure, get them to the hospital as soon as possible.

9. Lack of Sweating - One of the differences between heat exhaustion and full-blown heat stroke is a lack of sweating. If you’ve spent too much time in the sun, you’ll likely feel very hot. However, if you’re suffering from heat stroke, your body will not produce sweat, despite feeling incredibly hot.

10. Severe Headache - If you’ve spent time in the sun and you’re experiencing a severe headache, you may be suffering from heat stroke. It’s common for individuals to have a slight headache after spending time outdoors in the summer but a severe headache, combined with at least one other symptom on this list is an indication you need to seek medical attention immediately.