Environment Canada has issued a heat warning for majority of the Dehcho region over the long weekend, including Fort Liard, Fort Simpson, Fort Providence, Kakisa, Nahanni Butte, and Jean Marie River.
Public alerts said temperatures from Friday to Monday are expected to exceed 29C with overnight lows of at least 14C in these communities.
Temperatures are expected to return to normal by Tuesday.
The alerts warns that heat warnings will likely expand to other regions in the territory in the coming days.
Environment Canada issues heat warnings when high temperatures or humidity conditions pose an elevated risk of heat illness including heat stroke. The risks are higher for young children, older adults, pregnant people, people with chronic illnesses and people working or exercising outdoors.
Signs of heat illness include swelling, rash, cramps, vomiting, fainting, extreme thirst, rapid breathing and decreased urination. Anyone feeling dizzy or disoriented due to the heat should seek medical attention.
The chief public health officer is advising people in affected communities to wear loose-fitting light-weight clothing, stay hydrated, close windows and curtains during the hottest hours, use air conditions or fans, and schedule outdoor activities for cooler parts of the day. People and pets should also never be left inside a parked vehicle during high temperatures.