Some good advice above Geoff. A couple of points to add (though I haven't flown at all for about 3 years, I used to be a very frequent business traveller, just about world wide):
1. Re hand baggage: Whether or not you get charged depends an awful lot on which airline you're flying with, and which class (F, C, or Y) you've booked. Some airlines WILL definitely charge (or some even not allow) hand bags above certain sizes/weights - no ifs, buts, maybes (I have good cause to know this as I often had a lot of fragile carry-on kit). It is therefore VITAL that you contact the chosen airline in advance to find out exactly what they will/will not do for you in your particular circumstances.
2. Get your GP to give you a document detailing IN FULL your name address, phone number, Passport Number, exact medication name, daily dosage, etc. Get the GP to do it on his official headed paper and to add as many official-looking stamps and signatures to it as is possible/reasonable - the more official it looks the better. Reason is that even if the airline itself is not interested in such documentation, you will have Customs inspection on arrival. There's a high chance they will be interested in "weird-looking" stuff in your bags, especially if it could be "drugs". And there's also the check-in procedure on departure - just as/even more onerous.
3. Depending on what arrangements the airline makes with you before departure, it MAY be necessary to split your total package of meds into 2 parts - smaller for carry on, larger for hold baggage. I agree with the others that you should not do this unless absolutely necessary, but if your checked bags do go missing you'll have (say) a couple of days supply, minimum, + hopefully time for the airline to find your bag - AND the above document gives you a start point for buying new locally if your bag is completely gone.
4. Make sure your insurance will cover your extra (meds) cost if 3. above does happen.
5. Despite what others have said above, I can 100% assure you that ALL baggage holds in ALL modern pax aircraft are definitely both pressurised and heated. BUT - according to what else is loaded on your flight (a lot of airfreight travels on virtually all pax flights), the pax cabin pressure (altitude) will be held at about 8,000 ft, whereas the baggage holds will be higher (i.e. less pressure - perhaps 12,000 ft altitude). Ditto temperatures - pax cabin about 18 C, (in cruise); holds perhaps 8 or 10 C (again depending other cargo loaded and airline's own policy - more heat & more pressure in holds burns more fuel).
6. Lastly, not specific to you, check the expiry date on your Passport please. Last time I went there they wouldn't let you in if your Passport had less than 6 months to run before expiry.
7. I use a repellent called "Anti-Brum". In a small self-pump spray bottle. Stinks for the 1st 5 mins but very good. No idea if it's available in UK, sorry.
Enjoy your trip, it'll be great (once you're clear of that horrendous noisy circus called Manilla International Airport).
AES
