Philadelphia is bracing for a significant heat wave this week, with temperatures expected to soar into the 80s and 90s°F (27-37°C), potentially breaking temperature records for this time of year. Following a mild and sunny Sunday with temperatures in the mid-60s°F (around 18°C), a high-pressure system is set to trap warm air over the region, leading to several days of consistently high temperatures. The National Weather Service has issued advisories, urging residents to prepare for the elevated temperatures, which can pose health risks, especially for vulnerable populations like the elderly, children, and those with pre-existing health conditions.