Know the signs of heat stroke and heat exhaustion as record-breaking temps grip the U.S.

Much of the U.S. is bracing for a scorching heat wave with record-breaking temperatures expected in at least 14 different states. In some areas, the heat has already proven deadly. Maryland officials say two people suffered heat-related deaths this week.

CBS News' Dr. Tara Narula told "CBS This Morning" that people should be on the lookout for a number of symptoms that signal heat-related illnesses like heat cramps, heat exhaustion and heat stroke. 

In extreme heat, our body's protective control system can become overwhelmed, Narula explained. This puts our core temperature at risk of climbing without any checks. 

"So heat stroke is when your core temperature is 104 or higher and you start to have central nervous system dysfunction. At those higher temperatures, basically, your cells start to break down, your gut becomes leaky. You risk muscle damage, kidney, liver, brain damage and even heart damage," Narula said.

If you see someone you think is suffering from a heat-related illness, Narula said you should call 911 and start to cool their core body temperature by any means necessary. 

"And this is a real medical emergency so if you see someone suffering, call 911 and start to cool them by any mechanism you can. Get them into a cool bath, put cool sponges or cool blankets on them, really try to get their temperature down to 101 or 102."  

Heat cramp warning signs

• Headache
• Dizziness
• Nausea

Heat exhaustion warning signs

• Sweating
• Dizziness
• Fainting

Heat stroke warning signs

• Sweating
• Spasms
• Pain