Phone-based emergency tools

01 — Offline maps: navigation that does not need a cell signal

Once downloaded, a map area lives on your phone's storage and works with GPS, a satellite-based system that needs no cell connection at all. The download is what takes internet; the navigation afterward does not.

Both major map apps support this. On an iPhone running iOS 17 or later, open Apple Maps, search the area you want, and tap Download when the option appears; the same process applies in Google Maps on either platform, accessible through your profile menu under Offline Maps. Do this for your home area, your most likely evacuation routes, and any destination you might need to reach, while you still have a strong Wi-Fi or cellular connection. Trying to download a map area after the connection is already gone defeats the entire purpose.

• Turn-by-turn directions, place information, and estimated arrival times all work offline, as long as your entire route stays within the area you downloaded. Step outside that boundary and navigation stops until you reconnect.
• Live traffic, real-time road closures, and transit schedules do not work offline. An offline map shows the road network as it existed when you downloaded it, not what is happening on those roads right now. This matters specifically during an evacuation, where a route that was clear yesterday might not be clear today.
• GPS itself can take longer to find your location when you are fully offline. Normally, your phone uses a system called Assisted GPS, which borrows data from nearby cell towers to lock onto your position in roughly 5 to 15 seconds. Without that assist, the phone has to read positioning data directly from GPS satellites at a much slower transmission rate, which can stretch that initial lock to several minutes. Once it locks on, it works fine; the delay is only at the start.
• Refresh your downloaded maps periodically when you have a connection again, since roads, addresses, and points of interest change over time and a map downloaded years ago may no longer match reality closely enough to be useful.

02 — Wi-Fi calling: a second path to the phone network when towers fail

Wi-Fi calling routes your regular phone number's calls and texts over any internet connection instead of a cell tower. The feature is built into virtually every modern smartphone and every major U.S. carrier supports it, but it has one setup step people consistently skip: registering your address for 911.

When enabled, your phone automatically uses Wi-Fi calling whenever cellular signal is weak or absent but a Wi-Fi network is reachable: your own router (if it still has power), a neighbor's network, or a business offering public Wi-Fi. The call or text travels over that internet connection instead of the cell network entirely, which means a damaged or overloaded cell tower no longer determines whether you can reach someone. To enable it on an iPhone, go to Settings, then Cellular, then Wi-Fi Calling. On Android, the path varies slightly by manufacturer but is typically under Settings, then Network and Internet, then Wi-Fi Calling.

Calls and texts placed over Wi-Fi calling do not use your cellular data allowance, and there is generally no extra charge for standard domestic use. If you place an active call and then move out of Wi-Fi range, many modern phones (recent iPhone and Android models particularly) hand the call over to cellular seamlessly without dropping it; older devices may not manage that handoff as smoothly.

03 — Wireless Emergency Alerts: built in, automatic, and harder to dodge than a phone call

WEA messages reach your phone through a different delivery technology than a regular text, called Cell Broadcast, which is precisely why they get through even when text and call networks are jammed with traffic.

A standard text message is sent to one specific phone number and can get stuck behind every other text competing for the same network capacity. A WEA message works differently: the cell tower itself broadcasts it simultaneously to every compatible phone in range, the same way a radio station broadcasts to every receiver tuned in, rather than addressing each phone individually. This is the technical reason WEA messages reliably get through during the exact high-traffic moments when ordinary texts and calls struggle.

No app, signup, or subscription is required. If your phone is WEA-capable (virtually all phones sold in recent years are) and your carrier participates, you receive these automatically. The system organizes messages into four classes, each with a different level of urgency and a different ability to be turned off.

• National Alert. Issued by the President or FEMA's Administrator during a national emergency. This is the only category you cannot opt out of under any circumstance.
• Imminent Threat Alert. Covers extreme weather, wildfires, flash floods, and similar fast-moving dangers requiring immediate action. Can be turned off in phone settings, though the FCC specifically recommends against it.
• Child Abduction Emergency/AMBER Alert. Time-sensitive bulletins issued during active child-abduction cases, broken into several subtypes depending on the circumstances of the disappearance.
• Public Safety Message. Practical guidance tied to one of the categories above, such as a shelter location or a boil-water notice. Also optional to disable.

A WEA message looks like a text on your screen but arrives with a distinctive tone and vibration pattern, repeated twice, specifically designed to stand out from a normal notification. Your device stores each alert for at least 24 hours, so you can find shelter locations or other practical details again later without needing to remember them on the spot. The system will not interrupt an active call to deliver an alert, which keeps you connected to whoever you are already talking to, including 911, rather than yanking your attention away mid-conversation.

04 — ICE contacts and Medical ID: your phone speaking for you when you cannot

A single toggle, called Show When Locked, is what makes your phone's emergency information visible to a first responder without ever needing your passcode. Most people who set up this information never flip that toggle, which means the data sits there but stays invisible exactly when it matters.

First responders are specifically trained to check a locked phone's lock screen for an Emergency option, because this feature is now standard enough to be a routine part of on-scene assessment. On an iPhone, this lives in the Health app under Medical ID; tap Edit, fill in conditions, allergies, medications, and emergency contacts, then make sure Show When Locked is switched on. Without that toggle enabled, the same information you carefully entered remains hidden behind your passcode, defeating the entire purpose. On Android, the equivalent is typically found under Settings, then Safety and Emergency (the exact path and label vary by manufacturer), with the same "show when locked" option to enable.

• What a responder actually sees is narrow and deliberate. Tapping Emergency, then Medical ID on a locked phone reveals only the medical and contact information you entered, never your texts, photos, email, or anything else behind your passcode. This boundary is built into the feature specifically so that enabling emergency access does not mean exposing your entire phone.
• iPhone offers an additional layer: Share During Emergency Call. When enabled, calling 911 from the device automatically transmits your Medical ID information to the dispatcher, without any extra action required from you or anyone helping you in the moment.
• Include the basics that change an immediate medical decision: allergies (especially medication allergies), chronic conditions, current medications, blood type if known, and at least one emergency contact with their relationship to you noted.
• Keep a physical backup alongside the digital one. If your phone is dead, lost, or damaged in the same event that caused the emergency, the digital version is unreachable. A simple wallet card or a note on the refrigerator with the same core information is a low-effort second layer that costs nothing to maintain.
• Test it once after setting it up. Lock your phone, tap Emergency, then Medical ID (or the Android equivalent), and confirm your information actually displays the way you expect. A feature that silently failed to save is worse than no feature at all, because it creates false confidence.