Confirm what you are looking at

Do not rely on bites. Bite reactions vary enormously between people and are not diagnostic. Look for physical evidence with a flashlight: small dark rust-coloured spots along mattress seams and piping, pale shed skins, eggs, and live insects in the tufts, in the folds of the box spring, in the frame joints and behind the headboard.

What not to do tonight

• Do not throw the mattress out yet. NYC Health says you can in most cases treat furniture, and that you should only throw it away if there is no acceptable treatment or a professional advises it. Moving it through the building also spreads potentially infested material through common areas.
• Do not start moving bedding, clothing and belongings into other rooms. Moving potentially infested items is how one room becomes three.
• Do not take your things to a friend's or relative's home.
• Do not set off a fogger.

One thing that does help tonight

Run bedding and washable items from the affected area through a hot dryer for around thirty minutes. EPA supports high heat for suitable fabrics and notes that washing alone may not be enough. Bag what you have dried and keep it sealed.

Report it promptly

HPD identifies prevention, early detection and rapid treatment as the surest strategies, and bed bugs can move between apartments.

Expect follow-up rather than assuming one visit finishes it. NYC Health specifically tells building owners to be wary of anyone promising a one-visit solution.

If a neighbor has them

Ask to be inspected, especially if you are directly next door, above or below. NYC Health advises building owners to notify and inspect surrounding apartments when an infestation is found. Say yes to an inspection if it is offered, and ask for one if it is not.