Hoping to find a source for accurate glass Oral Thermometers to keep in First Aid kits. (We've all seen the cheap digital versions and the last time we needed ours, the battery was nearly dead, making the whole thing worse than useless.)

I've seen reviews for several glass thermometers that have accuracy problems and "shake down" issues. I won't care whether the adult version is mercury or mercury-free, so long as it's accurate. I'll be happy to procure also (for completeness' sake) a mercury-free pediatric version.

I'm hoping to procure "Cool Tool" grade, heirloom-quality, eternally accurate thermometers, hopefully with a rigid removable sheath/whatever to keep them intact forever.