This episode has a wealth of information and screen footage about Voyager.

When environmental controls fail, heat from the warp plasma conduits cannot be vented, resulting in a temperature rise throughout the ship.

Chakotay orders a level-4 quarantine on Deck 2.

The messhall is on Deck 2, Section 13.

Environmental control is on Deck 12.

Janeway goes to use the X-Y translation pad in the turbolift. Use of this manual control with touch interface is first seen in [#19 Twisted]. Its description comes from ST:M and TOSTFF.

X-Y translation pad

A hatch on the top of a turbolift car enables occupants to make an emergency exit, although it is awkward. Janeway goes to remove the hatch though is not seen actually doing so, nor is the escape made by her and Neelix shown. Emergency exit via the hatch is seen in [TNG: The Disaster]. The view of the top of the turbolift car in that episode is used in [#128 One Small Step].

Janeway looks up to where she must remove the hatch.

Quite a lot of the network of Jefferies tubes is seen in this episode. To get from the Jefferies tube by sickbay to Deck 12, the Doctor has to use Jefferies tube 11, take a left at Section 31, and straight down past the tractor beam emitter until he reaches Deck 10. He leaves the Jefferies tube at Section 3 and follows the corridor all the way around until he hits the shuttlebay. Then he crawls through Access Port 9, past three airlocks, and then two decks down. The environmental control is at the end of the hall.

the three pictures below show part of the network of Jefferies tubes

The ship's computer, accessed from the science station on the bridge, shows lifesigns in the messhall on Deck 2, the cargo bay on Deck 4, and the cargo bay on Deck 10.

One of the bio-neural gel packs in the messhall is ruptured due to the virus. Part of the circuitry and the infected gel pack are seen.

circuitry and gel pack

More of Neelix's cooking equipment and serving dishes are seen in this episode.

cooking equipment etc.

An open engineering kit is seen in one of the corridors. There is no indication whether the equipment in it is complete or even standard equipment.

engineering kit

Janeway sets a tricorder to emit a thermal scattering signal to throw off the viruses.

There is a weapons locker (or a metal box with lid - we are not told in the series exactly what a weapons locker is; a variety is seen in Star Trek) on the second floor of engineering (not there in other shots of that area in other episodes).

open weapons locker

The Doctor creates an antigen bomb as the means to deliver the substance. Janeway hurls this into the holodeck to which the macroviruses have been lured.

antigen bomb; includes countdown indicator
This screenshot also shows Voyager's corridor carpet in close-up detail

here is another close-up of Voyager carpet, this time on the bridge;
the boot belongs to Janeway, indicating scale of picture

When Janeway and Neelix return to the ship, they find the main computer and communications system offline. Main power is failing and the environmental controls go offline as systems start to shut down one by one.

A Tak Tak torpedo destroys the secondary power couplings taking the environmental controls offline.

Janeway's antigen bomb causes heavy damage to holodeck 2 but there are no hull breaches in evidence as a result.

According to Starfleet guidelines for an away team, if there could be a "medical emergency on alien terrain" it is recommended that the away team keep an open com channel at all times. Away team guidelines also specifically forbid the transport of unknown infectious agents onto a starship without establishing containment and eradication protocols.