With dangerous heat expected to settle into southeast Wisconsin this week, some homeowners were already stocking up on fans and air filters Sunday as HVACcompanies prepared for an increase in service calls.TMJ4 meteorologists ar e forecasting temperatures in the 90s beginning Monday, with heat index values topping 100 degrees through much of the week.At Third Coast Heating Cooling in Waukesha County, service technician Erik Borum said the company is expecting a surge in "no cool" calls as temperatures climb."We prepare for it, and that's why we say things like check your filters," Borum said.Borum said homeowners should think of an air conditioner like a car routine maintenance can help it perform at its best when demand is highest.One of the simplest steps, he said, is replacing a dirty air filter.Borum said clogged filters account for nearly half of Third Coast's "no cool" service calls."It's cheaper to change out an air filter than a motor," he said.He also recommends clearing grass, leaves, and other debris from around an outdoor condenser to maintain airflow.During a heat wave, Borum said homeowners should set their thermostat between 72 and 76 degrees and avoid constantly adjusting it, which can make the system work harder."The hotter it is, the harder your system's working to keep up with that," he said.Closing blinds or curtains during the hottest part of the day and waiting until after sunset to use heat-producing appliances can also help reduce strain on an air conditioning system, according to a post by Third Coast.TMJ4 has also reported that people should stay hydrated, limit time outdoors during peak heat, and check on older adults, young children, and others who are more vulnerable to heat-related illness.This story was reported on-air by Kaylee Staral and has been converted to this platform with the assistance of AI. Our editorial team verifies all reporting on all platforms for fairness and accuracy.Its about time to watch on your time. Stream local news and weather 24/7 by searching for TMJ4 on your device.Available for download on Roku, Apple TV, Amazon Fire TV, and more.Report a typo or error // Submit a news tip ...read more read less