ORLANDO, Fla. — When family members went to check on their loved ones at an assisted living facility called Grand Villa of Altamonte Springs last weekend, they were shocked to find their relatives’ rooms lacked power and air conditioning. Under a 2018 Florida law, nursing homes and assisted living facilities are required to have an emergency plan and a backup power source to keep temperatures at or below 81 degrees Fahrenheit for at least 96 hours in the event of a power outage. The law was made after around 12 nursing home residents died of heat-related illnesses during a power outage caused …