I live in a 22 story condo. I just moved from the 19th floor to the 20th. This was not an issue on the 19th floor. Very often the cold water in the kitchen comes out hot. Not just for a few seconds but I have to let the water run for a few minutes. It is a single faucet. Also, sometimes the water in the toilet tank is warm as well. It happens in the evening after it is cool outside or in the early morning so I don't think it has any connection to the sun's heat.
Thank you.
Doreen

Someone has a crossover on a faucet somewhere. I have seen moen single handle chateau's do this while off in the middle position. Other than that, someone may have an apparatus to get instant hot water and it is using the cold side for recirculation.

Uncross you lines under your sinks they are mixed up as for the toilet well at least you'll be warm

doreenc - Have land lord or owner to do repairs, hot water going to the toilet is going to desolve the wax ring ,the water is going to leak at bottom of toilet at the floor, OH THE COST OF FLOOR REPAIR. Good luck, F.B.E.