VANCOUVER — Nearly all of British Columbia is under a heat warning as Environment Canada urges people to prepare for what it describes as "dangerous" temperatures. Weather records are expected to be broken this weekend, with the mercury rising to new heights. “This is not something we take lightly. These are unprecedented temperatures, which we’ll be experiencing this weekend and into the early part of next week. We do need to take caution in terms of our health,” said Bobby Sekhon, a meteorologist for Environment Canada. Temperatures are already above average and it’s going to get hotter in the coming days. Daytime highs are expected to range from 29 to 38 C this weekend, with overnight lows of 18 to 21 C. Humidex values will reach the high 30s to possibly the low 40s. Health officials are warning people to avoid being in the sun for long periods of time to prevent heat exhaustion or even heatstroke. “I want to underline that heatstroke is a life-threatening emergency. So call 911 to get the person to the hospital immediately,” said Dr. Melissa Lem on CTV Morning Live. The symptoms of heatstroke include dizziness, fainting, nausea, vomiting, heavy breathing and increased heart rate. “While you're waiting for the ambulance, cool them down however you can. So get them into the shade, take off extra clothing. Put them in a cold bathroom shower or even apply ice packs to them,” said Lem. She’s also encouraging people to wear hats, sunscreen and sunglasses. Lem says avoiding strenuous exercise outdoors is also important. "Try not to exercise outside as much as you can when it's really hot, but if you absolutely have to make it safer by choosing an early morning or an evening workout exercise in a shady area, or even indoors when it's air conditioned and remember again to take lots of breaks,” she explained. Staying hydrated will be vital this weekend, but doctors are urging against caffeinated and alcoholic beverages. "Although a cold one might seem like a refreshing idea. In the heat, drinking alcohol can actually increase your risk of heatstroke because it's a diuretic. So consuming 10 grams of alcohol which is less than what it is in a standard drink mix makes your kidneys produce 100 milliliters or about half a cup of urine in return,” she explained. Kids under the age of four and adults over 65 are most susceptible to heatstroke, so health officials are urging people to keep an eye on their friends, family and neighbours. They’re also reminding people to never leave pets or anyone else in a parked car, because it can get dangerously hot inside within minutes. Environment Canada expects the heat wave will last until at least Wednesday.