For the next three to five days, temperatures are expected to reach 105 degrees Fahrenheit and above, according to the San Bernardino Department of Public Health. Due to the extreme heat, officials are issuing a warning for heat-related illnesses, such as heat stroke, especially for the elderly and young children.

Hyperthermia, or heat stroke, occurs when the body absorbs heat faster than it can regulate it. Once the body reaches 104 degrees, it is overwhelmed. By 105 degrees, brain death begins, and certain death occurs at 113 degrees.

To help stay healthy, it is recommended that people drink plenty of drinks, but avoid alcoholic and very sugary drinks. Be sure not to overwork yourself and to wear light-colored, loose-fitting clothing when outside, as well as sunscreen and a wide brimmed hat. When at home, wear as little clothing as possible while having the air conditioner on. And keep an eye on those who are at risk, such as infants and children under 4 years old, people over 65, people who are ill or on certain medications, people who are overweight and people who work outdoors.

Signs of heat exhaustion include heavy sweating, muscle cramps, weakness, headaches, nausea, vomiting, paleness, tiredness or dizziness.

If you believe you're about to, or are experiencing a heat stroke or over-heating, get to a shady area, use any methods available to cool off and call for medical assistance if signs of a possible heat stroke occur.