This EV suit design was used in arctic conditions on otherwise class M planets in the 23rd century. It could also withstand short exposure in an environment of flaming heat. A removable breathing mask was provided for use when atmospheric conditions could cause choking from the rapid condensation of vapors in one's breath. In such cases, speech would be impossible, so a portable radio unit in the uniform provided mechanically-transmitted telepathic relay communication between landing party members. The suit had a belt with small pouches to carry a phaser and other small equipment, as well as a heat stabilizer tablet to ingest when needed to compensate for unusual temperature variations. The uniform boots bound to ice without slipping, but could be disrupted by excessive amounts of heat.
Anti-freeze uniforms were worn in the year 2266 by a landing party visiting Floe I, reputed to be the coldest inhabited world in the Federation. The planet was in an expanding orbit which carried it outward from its sun. The mission was expected to be routine, but curiosity about the fast metabolism of the Floe in arctic conditions intrigued Dr. Krisp, who asked to join the team and was familiar with the operation of the uniforms. Unbeknownst to the landing party, however, the planet had traveled so far outward that the civilization was in its final days. (TOS comic: "Ice Journey")