Sony Xperia X Manual page 44

If battery does not charge after specified time, stop charging.
Internal Battery may leak, overheat, burst, ignite, etc.
Do not use handset when it may affect vehicle's electronic equipment.
Handset use may affect devices and lead to unsafe driving.
If you experience any skin irritation associated with handset use, stop handset use and
consult a doctor.
Metal and other materials may cause skin irritation, rashes, or itchiness depending on your physical
condition.
Keep handset away from magnetic cards, etc.
Data on bank cards, credit cards, telephone cards, floppy disks, etc. may be lost.
Do not swing handset by Strap, etc.
Handset may harm yourself or others, or Strap may break resulting in injury or handset malfunction/
breakage.
Avoid a prolonged use of handset in a place where temperature becomes high (e.g. near fire,
heater appliances, in the direct sunlight, inside sun-heated car, etc.), warm or overheated
(under kotatsu, electric blanket, near pocket warmer). Handset may become hot.
Prolonged contact with skin may cause low-temperature burns.
Handset or AC Charger (optional accessory) may become hot when calling or using
application (game etc.) while charging. Avoid a prolonged touch of the hot section.
Prolonged contact with skin may cause low-temperature burns.