Depending on what you are using for a dish it could be so cold that it's cooling down the temps of the rat. I'm guessing by 60 degrees you mean degrees Celsius because 60 Fahrenheit is not enough. Also next time you could try to place the rat closer to the entrance of the hide he could be in, and I would put said rat in the enclosure at a time that he is active and he wouldn't be in a deep sleep and not noticing the rat there. How often are you offering him food? I wouldn't be trying to feed him every week as that may be too often, I would give him a bigger break, I've heard of people waiting a full month before feeding again in case the snake is on a strike but depending on how long your snake hasn't eaten I might not do that. Do you know if smake is loosing weight from not eating? Usually if it's a strike the snake won't lose much weight. I would keep an eye on smake's weight until he eats again so that you can monitor it! (: