UNIVERSITY OF MARYLAND BALTIMORE COUNTY

Cold Mode: making smartphones usable in freezing weather

A system-level mode that adapts touch targets, contrast and feedback for people using their phones in sub-zero temperatures, often with gloves on.

TIMELINE

Sep – Dec 2025

ROLE

UX Designer & Researcher

TEAM

Two designers: Aasmita Bhattacharya and me

CATEGORY

Mobile accessibility, interaction design

−4°FCalled MomStarted directionsSent a message8:42−4°FSearchSOSEmergency contactPhoneMessagesMapsCameraWalletWeatherMMomMobileIn 200 ftTurn right on Elm StOffice · 12 minStartAlexRunning late?On my way!QWERTASDFGZXCVB8:42Wi-FiBluetoothFlashlightAirplaneFocusCold ModeCold Mode activated8:42−4°FSearchSOSEmergency contactPhoneMessagesMapsCameraWalletWeatherMMomMobileIn 200 ftTurn right on Elm StOffice · 12 minStartAlexRunning late?On my way!QWERTASDFGZXCVB8:42Wi-FiBluetoothFlashlightAirplaneFocusCold ModeCold Mode activated1Swipe down from the topQuick settings, like any other toggle2Tap Cold ModeOne large tile, easy to hit3Feel the confirmationA toast and a stronger buzz4The interface adaptsLarger targets, SOS up topIt's −4°F outside.
Concept demo of Cold Mode in use. Shown here from quick settings; the design also puts the switch on the lock screen and behind a double-press of the power button. Illustrative, not a recording of a built product.

ON THIS PAGE

Overview

At a glance

Problem

Key decisions

Process

Solution

Learnings

OVERVIEW

Smartphone interfaces assume warm hands and precise taps. Below 0°F (−18°C), neither holds: gloves block or blur touch input, and cold fingers lose dexterity within minutes. Aasmita Bhattacharya and I designed Cold Mode, a setting people switch on when they head outside, much like airplane mode. It enlarges touch targets, strengthens contrast and haptic feedback, and keeps the phone usable from the lock screen onward without removing gloves. The work covers research, interaction design, a low-fidelity prototype and a usability study protocol. The study hasn't been run yet, so this case study focuses on the design and the reasoning behind it rather than measured outcomes.

AT A GLANCE

12 mm

Minimum touch target size across Cold Mode, including the keyboard

14–16 mm

Passcode key size, so people can unlock with gloves on

0°F

Test condition defined in our usability study protocol

Why phones fail in the cold

Illustration of a pair of winter gloves
Below 0°F (−18°C)The temperature range Cold Mode is designed for.
GlovesReduce precision, and many don't register on a capacitive screen at all.
FingersCold reduces dexterity, so input becomes slower and less accurate.
ScreensTouchscreens become less responsive at low temperatures.
The conditions Cold Mode is designed for. Glove illustration from our project presentation; thermometer animation “Thermometer Cold” by reyb on LottieFiles.

Cold affects the hands, not the intent

Research by Sarsenbayeva et al. showed that short exposure to cold reduces fine motor control in the fingers, while attention stays largely intact.

In practice, someone waiting for a bus in January knows exactly what they need to do on their phone but can't do it reliably. The usual workarounds each fall short: conductive gloves register a touch but are still too coarse for small targets, a stylus is one more thing to carry and drop, and voice input struggles with wind and background noise. The operating system doesn't help much either, since touch sensitivity settings are buried and the layout itself never changes. When we traced the full journey, one gap stood out above the rest: the problem starts at the lock screen. If someone can't enter a passcode with gloves on, every improvement after that point is out of reach.

What people reach for today
Conductive gloves
Register a touch, but thick fingertips still miss small targets.
Stylus
One more thing to carry and drop, and often unreliable on capacitive screens.
Voice commands
Unreliable in wind and noise, and awkward in public.
Phone settings
Interfaces stay the same in the cold. Touch sensitivity is buried in settings, and automatic tweaks like adaptive brightness do nothing for stiff fingers.
The four gaps Cold Mode answers
Precision
Small targets and fiddly gestures
Visibility
Snow glare and low contrast outdoors
Control
No cold-weather switch, like airplane mode
Getting in
The lock screen itself is unusable with gloves
Identified later, and the most critical
How people cope with their phones in the cold today, and the four gaps Cold Mode is designed to close.

Three decisions that shaped Cold Mode

01

Manual control over automatic adaptation

We made Cold Mode something people turn on themselves rather than something the phone triggers from sensor data. Findlater and McGrenere found that users preferred interfaces they could adapt over ones that changed on their own, and a layout that rearranges itself unexpectedly is hard to trust, especially when someone is already struggling to use it.

02

Access starts at the lock screen

Our first concept placed the toggle in quick settings, which still required unlocking the phone. We moved it onto the lock screen, added a double-press of the power button as a no-look shortcut, and enlarged the passcode keys to 14–16 mm with a wider touch tolerance.

03

Fewer, larger targets and simpler gestures

Every target in Cold Mode is at least 12 mm, informed by Fitts's Law and prior work on input with reduced motor control. Non-essential elements are hidden, frequent actions sit within thumb reach at the bottom of the screen, and gestures like long-press and swipe-to-confirm are replaced with single taps.

How the design took shape

01

Defining the problem space

We started from situational impairments, temporary limitations caused by the environment rather than by the person, and focused on extreme cold, where gloves and stiff fingers compound each other.

02

Reviewing research on cold and touch

Studies on cold exposure pointed to one clear priority: adapt the physical interaction first, through target size and input tolerance, before adding anything new to the interface.

03

Mapping the context with HAAT

Using the Human, Activity, Assistive Technology model, we mapped who is affected, what they need to do and where. It confirmed that the solution should be software already on the phone, not another accessory to buy and carry.

04

Exploring an essentials-only home screen

Our first concept reduced the home screen to five essentials (call, camera, maps, payment and an emergency contact), added stronger haptic feedback and limited input to taps.

05

Grounding decisions in prior work

We tied each design choice to existing research: manual control, target sizing for impaired motor input, high contrast for glare, and RainCheck as evidence that phones can adapt to environmental conditions.

06

Closing the lock-screen gap

Walking through the end-to-end journey exposed the unlock step as the real barrier. We redesigned entry into Cold Mode, specified sizes for every target, sketched the four core screens and wrote the usability study protocol.

Human
Stiff fingers, less feeling, gloves on. A temporary limit, not a disability.
Activity
Unlock, call, text, navigate, reach an emergency contact.
Context
Below 0°F (−18°C) outdoors, with snow glare and low light.
Assistive technology
Cold Mode: a software switch. Nothing to buy, nothing to carry.
We framed the problem with the Human, Activity, Assistive Technology (HAAT) model: the person, what they need to do, where they are, and the technology that supports them.

From locked phone to sent message

Four core screens, designed for gloved hands

The prototype covers the moment that matters most outdoors: getting from a locked phone to a call, a message or an emergency contact without taking gloves off.

Cold Mode turns on from a snowflake button on the lock screen or a double-press of the power button, and a stronger vibration plus a status badge confirm the change. The passcode keypad expands, the home screen reduces to search, a dedicated SOS tile and six large app tiles, and the keyboard spreads its keys further apart. Contrast exceeds WCAG 2.1 AA so content stays readable against snow glare.

Hand-drawn sketches: 1. Lock screen and 2. Large-key passcode
1. Lock screen2. Large-key passcode
Hand-drawn sketches: 3. Cold Mode home and 4. Messaging
3. Cold Mode home4. Messaging
The original low-fidelity sketches of the four core screens.

Lock-screen access

Turn Cold Mode on from the lock screen or with a double-press of the power button, with no unlock required.

Glove-friendly passcode

Keys of 14–16 mm with a wider touch tolerance, so near misses still register.

Emergency access first

A dedicated SOS tile sits above everything else on the home screen.

Stronger haptic feedback

Firmer vibration patterns, because gloves absorb the subtle feedback phones normally rely on.

Evaluation planDesigned, not yet run
DesignWithin-subjects: each person tries the standard interface and Cold Mode, in counterbalanced order
SettingEnvironmental chamber at about 0°F, same phone, standard medium winter gloves
TasksText a message, start navigation, call a contact, look something up, switch apps, reach an emergency contact
MeasuresCompletion rate, time, errors, System Usability Scale, follow-up interviews
Success barBetter completion, time and errors than the standard interface, and a SUS score above 70
The usability study we designed for Cold Mode. It hasn't been run yet, so this case study makes no claims about measured results.

Takeaways

Map the full journey before designing screens

Much of our early effort went into refining the home screen before we realized that gloved users are blocked one step earlier, at the passcode. Tracing the journey end to end, from pocket to completed task, would have surfaced that sooner, and it's now where I start on a new problem.

A strong rationale is not a validated result

Every decision in Cold Mode is grounded in published research, but it hasn't been tested with people in real cold yet. The next step is running the chamber study we designed, then moving to field testing with a wider range of gloves.

Areas of Improvements

Illustration of a toggle switch with a snowflake
Run the study
Start with the controlled chamber study, then move to field testing, where wind, snow and real gloves are harder to control than in a lab.
More than one glove
The protocol uses one standard medium-weight glove. Thicker and thinner gloves need to be tested as well.
Beyond Android
The prototype was scoped to Android. iOS would need its own implementation.
Other conditions
The same approach could extend to other conditions, such as a wet screen or bright sunlight.
Where Cold Mode goes next, based on the limitations we identified.

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Want the full story?

The screens shown here are redrawn from our original sketches. I'd be glad to walk you through the research, the trade-offs behind each decision and how I'd approach testing it.

itsmehersunitha@gmail.com

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