Northern Health is warning residents of Northern BC, including Haida Gwaii, to take care during summer heat waves.With more sunshine and high temperatures expected Sunday, chief medical health officer Dr. Ronald Chapman reminds people to be aware of the risks of getting too much heat or sun exposure.Symptoms of heat illness include rapid breathing, headache, weakness or fatigue, nausea and muscle cramps. People with these symptoms should move to a cool environment, rest and drink cool, non-alcoholic beverages. If symptoms worsen or are severe, they should visit an emergency room or their family doctor.More tips from Northern Health:. Drink lots of water and natural juices, even if you don't feel thirsty.. Avoid strenuous activity during mid-day.. Avoid going out in the blazing sun. Stay in the shade or wear a hat.. Use sunscreen.. Use a fan to bring in cooler air from outside.. Check on vulnerable relatives, friends and neighbours to make sure they aren't suffering from the heat.. Never leave babies, small children or pets in a parked car.For more information about heat-related health issues, including heat exhaustion and heat stroke, call 811 for health advice 24/7, or visit www.healthlinkbc.ca