hotter than a mouse in a wool sock

Hotter than a mouse in a wool sock is a figure of speech not often used nowadays but which means that it is very hot, whether speaking of the weather or something that feels hot to the touch like boiling water or food you just cooked. Hotter than a mouse in a wool sock is usually pertaining to it being a hot day and relates to the fact that a mouse stuck inside a wool sock would get very hot indeed.