Best ways to help dogs and cats in this heat

[Mexican cuties]

Got 3 massive fans on, but our older 12 year old cat still seems intent in laying in full sun, have brought her into the house with enough fans to take off, bit are there any signs of overheating to look out for in cats, luckily our sunloving chihuahua wee man knows when he has had enough and even for him its too much

Thank you