With the summer in full swing, a medical expert is warning Canadians that heat stroke isn’t something that only happens outdoors.

Indoor heat stroke is a heat-related illness that is caused when the body overheats by going over a core temperature of 40 degrees Celsius and is unable to cool itself down.

The condition can occur in homes that don’t have air conditioning, inside a hot vehicle or anywhere that doesn’t have a central cooling system.

In Arizona, two babies have died in hot vehicles in two separate incidents this summer. Proposed legislation has been tabled in the U.S. Senate that would require carmakers to build alarms that could detect if a child was left alone in the backseat of a vehicle after it is turned off.

Dr. Nadia Alam from the Ontario Medical Association says children and seniors are most vulnerable to indoor heat stroke because their natural ability to manage their body heat is not developed enough, or has started to fail.

For parents, unusual behaviour can be an early warning sign that a child isn’t cooling off properly, Alam says.

“If you see that your child is running around and sweating, or even if your child is sitting and sweating, that tells you that the environmental temperature … in your room is probably a bit too high,” Alam told CTV’s Your Morning on Wednesday.

“Get them to sit down, get them to rest, turn down the shades to block out the sunlight and bring down the temperature. You can even take a spray bottle with room-temperature water and spray them and fan them.”

The time to call 911, Alam says, is when a child begins to show signs of mental distress.

“If that’s not working, they’re becoming grouchy, they’re starting to cry, they’re lethargic … or they drop into a coma, have seizures – anything like that, call 911,” she said.

Signs and symptoms:

- Excessive sweating

- Unusual sleepiness

- Inability to cool off

- Dizziness

- Nausea

- Diarrhea

- Preexisting conditions such as, diabetes, heart problems, obesity, and other illnesses with a fever can make someone more vulnerable

How to protect against indoor heat stroke:

- Dress in light layers

- Stay hydrated

- Stay out of the sun

- Take breaks when doing physical activities

- Make sure there’s good circulation in a room

- Don’t bundle up children in extra blankets

- Use a spray bottle to spritz room-temperature water to cool someone

When to call EMS:

- Change in mental state, such as grumpy, crying or lethargic

- Seizures

- Coma