All brands of autosampler vials and caps are not designed for use in “extreme” temperatures. However, the temperature ranges of typical, commercially available autosamplers is entirely suitable for use with autosampler vials. These temperatures are never extreme.
For very low temperature storage (e.g. -80°C) of your samples, specialized vials or containers may be required. These include storage vials used in cryogenic applications which MicroSolv does not offer.
As for extreme heating, autosampler vials made of high purity borosilicate glass can handle temperatures up to 300°C but that does not take into account effects of your sample on the vial at high heat. It is prudent to test a few examples before full use of any vial or container at high heat. RSA™ brand vials should not be used with temperatures over 120°C.