It's one of two things: she's either just pushing you - she's entering the difficult part of puppyhood and so she wants to be with you and push boundaries or she is too hot, as you suggest.
You are two options for if she is pushing you and testing boundaries:
If you trust her not to accident overnight and you're happy for her to be in your room, there's no harm in leaving the crate door open so she can get in/out (but this will likely lead to her wanting to be IN the bed at some point - so be wary). Dogs always want more!!
Or, you'll need to ignore her when she whines (particularly if she's not weeing when you do let her out). She's learning that crying for you gets you (and you really don't want that!)
But it could also be heat, like you said. Puppies aren't good at regulating their temperature until they're 4(ish)months and even after that they do struggle. They can do it, but it's harder. She also has a tonne of fur (it's the poodle/spaniel curse tbh) so that won't be helping.
I imagine it's number one (she's pushing boundaries and wants to be with you). She is lovely though! Regardless of which option you do go for, remember to have fresh water available overnight.
FWIW, once mine were all clean through the night I got rid of the crate. Crate training can be useful, but it's not the be all and end all of puppy ownership!