Taking everyone's advice another step:
By the time you feel abnormal heat in the hooves, they have already been pulsing for a few days.
So to ease your mind, it would be a good thing for you to learn to take your horse's digital hoof pulse
I printed this information, laminated it and keep it at the barn because I know I won't remember all this First Aid: How to Take Your Horse’s Digital Pulse at the Fetlock
As the article states, it is good to take your horse's hoof pulse (and record it) when you know she's feeling good. That way you have a baseline established.
Having the records might also be an advantage in getting the vet to your house when something serious does happen because numbers don't lie and the vet knows you're serious
Hope this helps:)