How to recognize an opioid overdose, call 911, give naloxone nasal spray, place someone in the recovery position and stay with them, plus where to get naloxone without a prescription and how Good Samaritan laws work.

A plain-language first aid hub for apartment and city households: when to call 911 versus a poison center or doctor, the first steps for cardiac arrest, choking, severe bleeding, burns, allergic reactions, stroke and heart attack, how to build a home kit, how to get trained, and what to do while you wait for responders.

Getting stuck in an elevator is frightening but rarely dangerous if you stay inside and wait for help. Guidance from fire departments, the Elevator Escalator Safety Foundation, NFPA and Ready.gov on using the alarm and emergency phone, when to call 911, why you should never pry the doors or climb out, elevators during fires and outages, and planning for people with medical or mobility needs.

Most food poisoning passes in a day or two, but some cases need medical care fast. CDC and FoodSafety.gov guidance on common symptoms, staying hydrated, the warning signs that mean it is time to see a provider, who is at higher risk, botulism red flags, reporting an outbreak and keeping a small kitchen safe.

Nosebleeds are common in dry, heated apartments in winter, and most stop with simple pressure. MedlinePlus, American Academy of Otolaryngology and American Red Cross guidance on the right way to sit, how long to pinch, why not to tilt the head back, how to prevent repeat bleeds and the warning signs that need emergency care.

When a person is unresponsive but breathing normally, placing them on their side helps keep the airway clear. American Red Cross and American Heart Association guidance on when to use the recovery position, step-by-step instructions, what to do for a possible spinal injury, pregnancy and infants, and when to switch to CPR.

A knocked-out adult tooth can sometimes be saved if it is handled correctly and a dentist sees it fast. American Dental Association, American Association of Endodontists and pediatric dentistry guidance on handling and storing a tooth, why baby teeth are treated differently, and first aid for broken teeth, mouth bleeding and dental swelling.

Cleaning products, cooking splatters and flying debris all put eyes at risk at home. American Academy of Ophthalmology, Prevent Blindness, MedlinePlus and Poison Control guidance on flushing a chemical splash, removing small particles safely, protecting an eye with an embedded object and knowing when to go to the emergency room.

Dog and cat bites are common in cities, and bats and raccoons live closer than many people think. CDC and American Red Cross guidance on cleaning a bite, controlling bleeding, spotting infection, reporting the bite, the 10-day observation rule for pets and when rabies post-exposure treatment is needed.

Medical shock is a life-threatening drop in blood flow that can follow heavy bleeding, severe burns, allergic reactions or serious illness. American Red Cross, MedlinePlus and NIH guidance on the warning signs, how to position and keep the person warm, why to skip food and drink, and when to start CPR.