Plane travel advice: Will liquids leak in your checked-in luggage?

LONG AGO, UN-PRESSURISED AIRCRAFT BAGGAGE HOLDS CAUSED TRAVELLERS TO PACK LIQUID TOILETRIES IN PLASTIC BAGS SO THAT LIQUID LEAKAGE DIDN'T RUIN SURROUNDING ITEMS IN ONE'S SUITCASE. IS THAT STILL THE CASE? R. GOULD, WEST MELBOURNE, VIC

Baggage holds are pressurised these days, so no problem with liquids in sealed bottles rupturing and spilling their contents at the lower pressure encountered at high altitudes. The cylindrical shape of the fuselage is very efficient at maintaining a higher pressure inside and the entire fuselage in a modern passenger aircraft is pressurised. Live animals are frequently transported in cargo holds, unless they happen to be the pampered falcons of a Middle Eastern notable when they might occupy the entire first class, and pets obviously need to breathe. For exactly the same reason, the temperature in the hold is equal to that in the main cabin.