Heat packs or hot water bottle?

I have heating pads, but my students don't like using them.
If they want, I'll give a cup of warm water to drink and let them rest for a few minutes.
Fortunately for my students, not too many get cramps regularly (my school only goes to 8th grade).

i have an electric heating pad. The kids that come in with cramps really seem to get decent relief from it. My rule is that they have to come during an elective or reading period

I have a rice sock that I heat up!! works great and kids can take it to class and return it when done :-)
Just regular rice in a sock!

I like the use of heat, especially for menstrual cramps. But I don't know of any girl who is willing to use a heating pad or rice pack in class because it calls attention to the reason why it's being used.

At home I use Thermacare heat wraps for my girls, and I recommend them to parents whom I speak to. They are too expensive for my district to order, but they can be brought to school and used discretely.

Not a school nurse but these are good:

Bed Buddy Back Wrap or sinus pack. The sinus pack is small so they can "hide it" under a shirt when in class.

Bed Buddy Deep Soothing Sinus Pack with Strap Thermatherapy