Grab water and sunscreen as hot, sunny days expected in Waterloo region this week

Summer may not officially arrive until Friday, but it's going to feel like it's the middle of the hottest season this week as temperatures are set to rise to 30 C and higher in Waterloo region and area.

• Get the latest forecast for Kitchener-Waterloo from CBC Weather

A heat warning has been issued for the area asdaytime highs through much of the week are expected to be 30 C to 35 C with humidex values of 40 to 45. There will also be little relief at night as overnight lows are expected to be 20 C to 23 C.

Thehot and humid air mayalso bring deteriorating air quality, the warning said.

"We have a hot and humid air mass that will be settling into the area, a very big area,all of southern Ontario including Kitchener-Waterloo," meteorologistGerald Cheng said in an interview.

He noted hot and humid can also mean unsettled weather is possible over the course of the week.

"We have to watch for the possibility of severe weather and with severe weather, when we talk about thunderstorms, they can really change from day-to-day forecast. Yesterday might be changing today because of new data. So we have to monitor the situation," he said.

Along with the hot, humid weather, people also need to consider the UV index and ensure they're wearing sunscreen to protect themselves.

Ways to stay cool

The Region of Waterloo will issue a heat warning when:

• Two consecutive days where the temperature is forecasted to be 31C or higher during the day and 20C or higher overnight.
• Two consecutive days where the humidex isforecasted to be 40C or higher.

The region lists places people can go to cool off, including municipal buildings, libraries, sports complexes and community centres during regular operating hours.

Public health warns extreme heat can affect anyone, but in particular people at higher risk include:

• Older adults aged 65 and over.
• Infants and young children.
• People who work outside.
• People taking part in outdoor sports and activities.
• People with chronic illness.
• People who live alone.
• People experiencing homelessness.

It's recommended people wear light, loose-fitting clothing, get out of the sunlight and into shade and drink plenty of cool liquids to prevent heat-related illnesses.

Exposure toextreme heat and humiditycan cause:

• Dizziness or fainting.
• Nausea or vomiting.
• Headache.
• Rapid breathing and heartbeat.
• Extreme thirst.
• Decreased urination.

The region also notes people and pets should never be left inside a parked vehicle or in direct sunlight and people should check on vulnerable neighbours, friends and family members if they can.

Cheng says there will be people who love this week's weather and people who will dread it, but he says the best thing to do is have a sunny outlook on it and plan ahead by taking water, sunscreen and staying out of the sun at its peak during the day.

"I know that we like to complain about the weather, butbecause we can't choose what the weather is going to be, we might as well enjoy it," he said.