With Wednesday's forecast calling for a high of 33 and UV index of 10 - or very high, and Thursday calling for a high of 32 and UV index of 9, it's a good reminder to try and limit the amount of time you spend outside, especially without sunscreen.

The effects of heat illness include swelling, rash, fainting, heat exhaustion, heatstroke, and the worsening of some health conditions.

But that's just the heat, what about the UV index? What does it mean for our health?

The UV Index is a measurement used around the world, which gauges the strength of ultraviolet radiation over the course of a certain amount of time.

One of the most recognized symptoms of too much exposure to UV rays is the all-too-common, and painful, sunburn.

Terri Lang, Warning Preparedness Meteorologist with Environment Canada.

"When the UV index is moderate to high, we ask people to avoid the high-sun. The higher the UV index, the more quickly you will burn."

"It's a little bit deceiving because the maximum UV is always at high-sun time, which is noon to 1 o'clock, but the maximum temperature usually doesn't occur until 4 or 5 o'clock."

Lang adds that when the UV index is moderate to very high, and when the humidex is over 30%, people tend to feel lethargic and possibly weak.

This is due to your body not being able to cool itself down properly, and proper precautions should be taken.

Of course, with the increased temperatures and high humidity, there's also the chance for severe thunderstorms to develop. While the current forecast is only calling for the chance of a storm Wednesday night, the large storms can develop quickly, with only a few hours notice.