Summer is about to unleash a string of hot days across Maitland including one day over 40 degrees. Temperatures will reach 42 degrees on Saturday and rise up to 38 degrees on Friday. It will be 33 degrees on Wednesday and Thursday. Overnight temperatures will be around 17 degrees for the rest of the working week. The nights will be warmer on the weekend with overnight temperatures on Saturday falling to 23 degrees. There will be a 20 per cent chance of rain on Thursday and Saturday. The hot weather comes after NSW Health's Beat the Heat campaign, which offers tips to stay healthy during hot days. "Extreme heat can cause severe illnesses and can be life threatening," NSW Chief Health Officer Dr Kerry Chant said. "We ask our community to ensure they are prepared, know the symptoms of heat-related illnesses and take action to keep cool during heatwaves." Related: Dangers of a long hot summer Dr Chant said there were a range of things people could do to stay safe during the hottest parts of the day. These include closing doors, windows, blinds and curtains early to keep hot air and sun out, staying hydrated and carrying a water bottle when outside. "If it's hard to keep cool at home, plan to spend the day somewhere cooler, which might include public spaces like shopping centres, libraries or air-conditioned community venues," Dr Chant said. IN THE NEWS: Signs of heat-related illness can include headache, dizziness, nausea and vomiting, fatigue and cramps. Anyone with these symptoms is encouraged to find a place in the shade or air conditioning, take a cool shower or bath and drink sips of water. Those who don't respond to this treatment and those who become worse should seek urgent medical attention or call Triple Zero.