The HEV Suit,^[​1] or Hazardous EnVironment suit, often called the "Hazard Suit" for convenience, is a full-body hazardous materials suit developed at the Black Mesa Research Facility. Designed for Black Mesa scientists to protect themselves from radiation, energy discharges, blunt-force trauma during the handling of hazardous materials, and the effects of traveling to Xen as part of Survey Teams.

It is predominantly worn by Gordon Freeman during much of the Half-Life series - first as the Mark IV suit in Half-Life, then as the upgraded Mark V suit in Half-Life 2. It allows him to sustain many injuries from damage that would normally fatally wound him, such as projectiles or melee attacks.

The HEV Suit is related to both the Powered Combat Vest (PCV) used by the Hazardous Environment Combat Unit (HECU), and the armored vest and helmet used by the Black Mesa Security Force.




The HEV Mark IV suit worn by Gordon Freeman in Half-Life has a built-in flashlight, Geiger counter, morphine administrator (which allows Gordon to sustain serious injury such as bullet wounds or shrapnel), an optional Long Jump Module which allows jumps over large distances (greatly increased horizontal range; vertical distance is elevated only slightly), a radio, tracking devices, and a heads-up display (HUD) which tracks health status and weapon ammunition usage, as well as including a weapons management system.

The suit contains an on-board computer system that constantly monitors the user's health and vital signs, reacting to any changes in the user's condition with activations in the aforementioned apparatus, and a soothing female-computer voice.

Additionally, the suit has an electrically hardened armor/energy shield system that can be charged at HEV chargers throughout Black Mesa. While charged, the suit provides greater protection from injury as the charge absorbs more than two-thirds of any damage or trauma experienced by the wearer, with the exception of fall damage, which is absorbed directly into body-integrity, and oxygen deprivation, caused by swimming without surfacing for long periods of time. With a fully charged suit, Freeman can survive several dozen bullets of small arms fire, continuous fire or even a direct hit from a rocket-propelled grenade (but suffering about sixty percent damage).

The suit also features an optional helmet, as seen on various HEV-enclosed corpses dotted around Xen, mainly at the ruined research camp seen in Blue Shift. Although, when Freeman is spotted in Opposing Force, he enters Xen through the portal without wearing a helmet, such being the situation he would need it the most. Headcrabs will never attempt to attach directly to Freeman's head either (although, in the official Half-Life manual, Freeman never allows a headcrab to attempt to).

The HEV Suit is not exclusive to Freeman. Many can be seen worn by slain Black Mesa research members on Xen. Two additional (empty) HEV storage units are seen near the start of the game in Sector C, which are used by the main protagonists of Decay, Gina Cross and Colette Green and three empty HEV storage units can be seen near the end of Lambda Core.

The suits also come in different colors. Although many, including Gordon's and the ones belonging to the corpses seen on Xen, are orange, Gina wears a beige suit, while Colette wears a maroon suit.

Freeman dons the suit at the beginning of Half-Life, and is allowed to keep it at the end of the game by the G-Man.