Well, I always liked cool bedroom at night, and now that I’m approaching menopause I feel too warm more and more often at night. Unfortunately, my husband is exactly the other way around - he likes it warm or at least not cooling off noticeably during the night. We have different blankets already and I’m spending an awful lot of time trying to devise a temperature and window opening regime so we both can get a decent sleep. Now we bought this expensive new memory foam mattress, and while it has been very comfortable and good for our backs, it’s also much warmer. I feel like I’m lying on a warming pad and I’m getting desperate I’ll never get a good night’s sleep again. Do you have any solutions short of sleeping in different bedrooms? Are there any “cooling mattress toppers” that actually work but won’t make him too cold?
When my H began having trouble sleeping due to arthritic hip and shoulder pain, I bought this cooler type of mattress topper: https://www.amazon.com/gp/product/B00FJNQBJ2/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
I don’t find that it makes me either cold or hot.
Another solution may be to put a cotton mattress pad over your memory foam topper, for an additional layer between the topper and the bottom sheet.
A ‘Chillow’ (cooling pillow) was recommended by several friends.
Try a sheepskin topper for your mattress. I got one from Costco as it was about $120 and doctored our firm memory foam mattress with it. Even though I don’t have hot flashes, I prefer to be cool at night. Mr. B no longer complains that he is cold. 
I also highly recommend dual control heated mattress pads. That way you can have the room temperature colder and he can turn up his side of the bed.
You did say “any solutions short of sleeping in different bedrooms”.
I’ll just toss out there that we are loving having our own rooms! It has solved a wide range of minor incapability problems — temperature to morning alarms to lights out time. We are both sleeping much better.
@BunsenBurner - Unfortunately, we had a sheepskin topper before, and it got infested by clothes moths. Gross!
We are the opposite, DH has a fan on his side of the bed that blows directly on him and not me. Might that work ?
Egads! Never had anything eaten by moths. That’s terrible. We do keep the white cat out of the bedroom because she previously peed on small sheepskin rugs and in Uggs… to the delight of our dog.
OK, how about an electric blanket. H can turn his side on to his liking, you can keep yours off. You may want to try an eggcrate mattress toppers, I have found them very comfotable but they are cooler than the flat pad.
You could get a cooling mattress pad, twin size, for your side. Or the cooling pillow might be enough. I would think though that the best arrangement would be a cool room and extra blankets for your husband or a dual control electric blanket. It’s much easier to warm than cool!
Thank you everyone for helpful suggestions. I think the mattress is the most immediate problem, so I’ll try to get a cooling pad. I occasionally move to the guest bedroom when I don’t feel comfortable, and found that I do sleep better but I really hate being alone and on a different floor to boot.
I can’t sleep in a hot room. The head of my bed is against a window and that window is wide open all night no matter what the outside temperature. I have awakened with a snowdrift on the bed. This is non-negotiable. This predates menopause, I have always needed fresh air to sleep. My husband just piles on extra blankets on his side.
I really hate staying in hotels where the windows don’t open.
Wellspring, we are open window twins. 
We bought a Dyson fan for our bedroom for those nights what a simple open window won’t do. It is quite quiet for a fan!
ChillPad makes a cooling mattress pad (sort of like an electric blanket but it cools instead. Has a water flow through it I believe.