A heat warning for the nation’s capital is in effect this week, as hot, humid weather is expected to last through most of the week. The yellow-level warning calls for temperatures between 30 and 37 C, with humidex values of up to 45. “Tuesday will mark the peak of this heat event. Maximum temperatures on Tuesday near 37 degrees Celsius are expected for some areas over southwestern Ontario, around the Greater Golden Horseshoe and eastern Ontario. Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high-risk category,” Environment Canada says. The forecast for Monday calls for a high of 31 C with a humidex of 37. The sky should be sunny in the morning, but clouds could move in by the afternoon, with a 30 per cent chance of showers and the risk of a thunderstorm. There could also be some local smoke from wildfires. The air quality health index for Monday is 3, or low risk. The UV index is 7, or high. Overnight, expect a low of 21 C, which is about five degrees warmer than average, with a risk of a thunderstorm after midnight. Tuesday is looking sunny early in the morning, followed by a mix of sun and cloud with 30 per cent chance of showers late in the afternoon, and a risk of thunderstorms. The high is 35 C with a humidex of 43. Wednesday’s forecast is sunny with a high of 30 C. Thursday has a mix of sun and cloud and a high of 28 C. Friday’s outlook is sunny with a high of 26 C. Extreme heat brings health risks Environment Canada says extreme heat can be detrimental to one’s health, especially those at higher risk, including older adults and young children. To protect from the heat, Environment Canada recommends: Environment Canada says to be aware of the symptoms of heat stroke, which include red and hot skin, dizziness, nausea, confusion and change in consciousness.