Guinea Pig Emergency help?

So it's really humid today, and I know it affects guinea pig's health, because my guinea pig got sick from it once. So I read the signs, when she started running around looking for a cold place, and I soaked her in chilly water so she can cool down. I brought her to my mom's bedroom, and she was laying on my mom's stomach. Then she wanted to layed down on my mom's legs. When she did, she started to move weirdly, almost like she was trying to get up but couldn't. I picked her up and noticed that her head was tilted to the side and she couldn't move it. When I placed her on the ground her head stayed that way and she started to twirl around. I got scared because her eyes started rolling back into her head, and she started squeaking. So I held her close, and my dad brought a soaked towel and held her in it. She made some noises and calmed down, then I let her down on the kitchen tiles and she was ok. I don't understand what could've caused it and I don't even know what happened. She was perfectly fine and the next minute it seemed like she was parlayed or something. Should I be worried? Right now she's eating and drinking and she even started pop corning when I played with her. Should I be worried?